烟灰
ORIGINAL PAPER
Characterization of volatile organic compounds and odors by in-vivo sampling of beef cattle rumen gas,by solid-phase microextraction,and gas chromatography–mass spectrometry–olfactometry
Lingshuang Cai&Jacek A.Koziel&Jeremiah Davis&
Yin-Cheung Lo&Hongwei Xin
Received:24July2006/Revised:21August2006/Accepted:22August2006/Published online:29September2006
#Springer-Verlag2006
Abstract V olatile organic compounds(VOCs)and odors in cattle rumen gas have been characterized by in-vivo headspace sampling by solid-phase microextraction (SPME)and analysis by gas chromatography–mass spec-trometry–olfactometry(GC–MS–O).A novel device en-abling headspace SPME(HS-SPME)sampling through a cannula was designed,refined,and used to collect rumen gas samples from steers.A Carboxen–polydimethylsiloxane (PDMS)fiber(85μm)was used for SPME sampling.Fifty VOCs from ten chemical groups were identified in the rumen headspace.The VOCs identified had a wide range of molecular weight(MW)(34to184),boiling point(?63.3to 292°C),vapor pressure(1.05×10?5to1.17×102Pa),and water solubility(0.66to1×106mg L?1).Twenty-two of the compounds have a published odor detection thresholds (ODT)of less than1ppm.More than half of the compounds identified are reactive and have an estimated atmospheric lifetime of<24h.The amounts of VFAs, sulfide compounds,phenolic compounds,and skatole,and the odor intensity of VFAs and sulfide compounds in the rumen gas were all higher after feeding than before feeding. These results indicate that rumen gases can be an important potential source of aerial emissions of reactive VOCs and odor.In-vivo sampling by SPME then GC–MS–O analysis can be a useful tool for qualitative characterization of rumen gases,digestion,and its relationship to odor and VOC formation.
Keywords Rumen gas.Odor.In-vivo sampling.SPME. GC–MS–O
Introduction
Rumen headspace is saturated with compounds produced during digestion.Feed in the rumen is degraded by fermentation processes resulting from physical and micro-biological activity that digests feed under anaerobic conditions.The products formed could be useful(VFAs, microbial proteins,B-vitamins),useless(CH4,CO2),or even harmful(ammonia,nitrates)to the host animal[1]. Because the composition of ruminal fluid affects digestion processes,it is important in nutritional studies.Feed utilization and feed additives can effect gas emissions from manure,and thus its odor.Cattle production is associated with emission to the atmosphere,of odor compounds, VOCs,and other gases originating mainly from manure and from the animals themselves.The chemical composition of rumen liquid and gas can affect air quality.Rumen gas can be released to the atmosphere by eructation and in exhaled breath.Digested products from the rumen can be also released with manure and can,therefore,be a source of aerial emissions of VOCs and odor.
Numerous methods are available for collection of rumen fluid for analysis.It can easily be collected through a cannula surgically placed in the rumen[2].Other approaches for animals without rumen cannula have
Anal Bioanal Chem(2006)386:1791–1802
DOI10.1007/s00216-006-0799-1
L.Cai
:J.A.Koziel(*):J.Davis:Y.-C.Lo:H.Xin Department of Agricultural and Biosystems Engineering, Iowa State University,
Ames,IA50011,USA
e-mail:koziel@https://www.wendangku.net/doc/fc11499882.html,
L.Cai
Department of Chemistry,Wuhan University,
Wuhan430072,People’s Republic of China
involved either the use of stomach tubes[3]or percutane-ous needle aspiration(rumenocentesis)[4].Both techniques are stressful to the animals.Samples taken by stomach tube are often contaminated with saliva[3]and rumenocentesis has occasionally led to infection[4].
Characterization of fermentation products is used to assess the extent and nature of the microbial fermentations [5].Several methods are used for the quantification of these products.High-performance liquid chromatography was used to quantify ethanol,n-butanol and VFAs in the early 1980s[6].Gas chromatography has been commonly employed to quantify VFAs and alcohols in rumen fluid [7–12]since the1960s.Most of these methods involve time-consuming sample-preparation procedures.Solvent extraction with ether[12]or dichloromethane[10]and pre-injection derivatization of acids[7,13,14]are often used.Sampling and analytical methods used in this and previous studies to determine rumen fermentation products in rumen fluid are compared in Table1[2,9–11,15–17].
Nearly all studies have focused on characterization of ruminal fluid itself.Relatively little is known about the composition of rumen gas and its implication for gaseous emissions.Sampling of gas instead of liquid is more challenging analytically.One benefit,however,is minimi-zation of the multiphase liquid–solid sample matrix which requires extensive sample preparation.Measurement of gases produced by rumen microbes could be very useful for evaluating diets,animal health status,feed additives, dietary amendments,and rumen fermentation[15].
Only one study has reported sampling and analysis of rumen gas to obtain information about rumen processes. Dewhurst et al.[15]investigated gases in rumen headspace by using active gas collection in two-liter food-grade poly (ethylene terephthalate)(PET,also referred to as Melinex) bottles with rubber stoppers for on-site and next day laboratory analysis using a selected-ion-flow-tube mass spectrometer.A total of14gases,including several alcohols,ammonia,five VFAs(from acetic to hexanoic), acetone,acetaldehyde,and H2S and other sulfides were reported[15].Potential sample-recovery problems and uncertainties associated with quantitative analysis of gas samples in rumen still exist with this approach and similar
Table1Comparison of sampling and analytical methods used to characterize VOCs in rumen gas and rumen fluid
Ref.Sampling Sample preparation Analysis Odor
analysis Identified compounds
This work SPME,cattle with rumen
cannula,in-vivo sampling SPME(Carboxen–PDMS);Extraction
conditions:39°C,5min
GC–MS–O Sniff
port on
GC–
MS–O
Cattle rumen
headspace,50
compounds
Dewhurst et al.[15]Cattle with rumen cannula,
rumen gas was pumped into
evacuated plastic bottles
(2L),in-vivo
The caps of the bottles containing the
rumen gas were punctured with a needle
connected directly to the inlet port of the
SIFT-MS
Selected-ion-
flow-tube mass
spectrometry
(SIFT-MS)
None Dairy cows rumen
headspace,14
compounds
Spinhirne et al.[16]Ruminal fluid from
cannulated heifer
SPME(DVB–Carboxen–PDMS);
Extraction conditions:39°C,1min
GC–MS None Heifer rumen fluid
headspace,12
compounds
Schneider et al.[17]Fistulated cow Centrifuged and filtered,reacted with
NaOH,then derivatized with
trifluoroacetic acid and extracted with
chloroform
GC–FID None Cow rumen fluid,
20compounds
Teunissen et al.[9]Fistulated sheep Filtered on a Whatman GF/C glass
microfiber filter and centrifuged.The
supernatant was pipetted into1.5-mL
Eppendorf reaction vessels and then stored
at4–10°C for up to48h
GC–FID None Sheep rumen liquor,
22compounds
Faichney et al.[10]Fistulated sheep
and cattle
Distilled and made alkaline with sodium
hydroxide,then evaporated on a hot plate
and dried,then dissolved in acetone
GC–FID None Sheep and cattle
rumen fluid,6
compounds
Williams et al.[11]–Centrifuged and extracted with
dichloromethane
GC–FID None Goat rumen liquor,
plasma,and tissue
of ruminants,2
compounds
Calabro et al.[2]Rumen cannula.Centrifuged and diluted with oxalic acid GC–FID None Buffalo and sheep
rumen fluid,4
compounds
conventional sampling methods,however,because of the porous nature of the polymeric materials used for sampling containers,adsorption by walls,condensation of and partitioning to water,reactivity of gases and reactions between gases inside the sample container,and false positives caused by gases emitted by sampling containers.
Poor sample recoveries for VFAs were reported when PET sampling bags were used[18–20].Mean gas-sample recoveries were66.1%for seven VFAs from acetic to hexanoic acid after storage for24h at room temperature in PET bags[18].Recoveries were27.6,61.4,73.9,51.1,and 38.2%for acetic,propanoic,butanoic,pentanoic,and hexanoic acids,respectively[18].PET bags were also not recommended for collection and24-h storage of H2S or ammonia[20].Alcohols,VFAs,and ammonia can also readily partition to water in air samples.Acetaldehyde is a reactive gas and is typically sampled by derivatization[21].
No olfactometry analysis of rumen liquid or gas has been reported in previous studies.Odor analysis could provide additional insight into the specific composition of the gas, especially when the human nose is more sensitive than conventional analytical detectors.Many compounds well known to be present in rumen liquid are also known to be offensive odorants and are emitted from manure.Thus,the link between specific diet,rumen gases,and livestock odor warrants research.
Solid-phase microextraction eliminates the use of sam-pling containers and combines sampling and sample prepa-ration into one step.Air sampling with SPME has many advantages over conventional sampling methods[22–25] because of its simplicity,reusability,very good sample recovery[18],and the hydrophobic behavior of SPME coatings.Koziel et al.[18]reported105%(±11.4%) average recoveries of gaseous VFAs(from acetic to hexanoic acid)at room temperature and after storage for 24h after use of75μm Carboxen–PDMS SPME fiber coatings[18].The variability(measured as standard deviation)for recoveries of VFAs were as low as2.0,3.6, 9.7,and 5.6%for propanoic,butanoic,pentanoic,and hexanoic acids,respectively.Spinhirne and Koziel used SPME to sample headspace gases from closed in-vitro cultures to evaluate ruminal fluid,and ruminal fluid after injection of feed containing an additive,by use of GC–MS [16].Spinhirne et al.[26]reported the use of SPME for on-site breath sampling of steers and characterization of21 VOCs[26].
This study was conducted to characterize volatile organic compounds(VOCs)and odors in cattle rumen gas by in-vivo sampling of the gas.In this research,a novel device enabling headspace SPME(HS-SPME)sampling through a cannula was designed,refined,and used to collect rumen gas samples from steers.Rumen gas samples were analyzed by use of a GC–MS–olfactometry system enabling simultaneous qualitative characterization of VOCs and odor[27–29].As far as we are aware,this is the first investigation of this kind to conduct in-vivo SPME and evaluation of rumen gas odor.
Experimental
Rumen gas sampling device
A novel device(Fig.1a–c)enabling headspace(HS)SPME sampling through a cannula was designed,refined,and used to collect rumen gas samples from three steers for three days.The device uses a cannula stopper modified with a sealed septum port for insertion of SPME fibers.The objective was:
1.to modify a typical cannula plug with readily available,
low-cost materials;
2.to make the modified plug easily removable for
replacement with a regular plug;
3.to make the modified plug safe for the animal while
sampling;
4.to make separation of the rumen gas and fluid possible;
5.to provide a means of SPME insertion into the sealed
rumen headspace;and
6.to protect the fragile SPME fiber assembly from
possible damage by floating undigested and partially digested feed and rumen fluid.
A PVC“snorkel”was constructed to protect the SPME fibers from contact with the mixture of rumen fluid and forage while enabling interaction of the fibers with the headspace gases.The main tubing and screen for the device were made from6cm diameter PVC tubing and bushings purchased from a local hardware store(Lowes,Ames,IA, USA).The“snorkel”was fixed to the cannula plugs with bushings.A3mm(1/8”)diameter bulkhead fitting (Swagelok,Kansas City,KS,USA)was mounted in the center of the plug.A Thermogreen half-hole septum (Supelco,Bellefonte,PA,USA)was inserted into the bulkhead fitting and held tight with the Swagelok nut to seal the SPME needle and to guide it into the rumen headspace.All dimensions are provided in Fig.1c. Sampling of rumen headspace gas with SPME
A Carboxen–PDMS SPME fiber(85μm)(Supelco, Bellefonte,PA,USA)was used for rumen headspace gas sampling.The Carboxen–PDMS coating has proven to be very effective for extraction of VFAs and sulfides[30,31], i.e.the types of compound known to be in rumen gas[15]. Carboxen has small-diameter(10?average)pores which
are suitable for adsorption of molecules in the C 2–C 12range [24].Fibers were conditioned in accordance with the manufacturer ’s instructions.Fiber assemblies had their tensioning spring removed and samples were collected manually,i.e.without the SPME holder.Before sampling,the fiber was desorbed for 5min at 260°C,then wrapped in clean aluminium foil.Tight wrapping of SPME assemblies in aluminium foil sealed the fibers from the ambient environment.The operator wore nitrile gloves and avoided direct contact with the SPME needle to minimize interfer-ences.SPME fibers were transported to and from the laboratory enfolded in aluminium foil,placed inside a
clean
Fig.1Schematic diagram of device for in-vivo sampling of rumen gas by SPME.a Cattle rumen with modified cannula and SPME sampling device.b Cross-section of rumen.c Modified cannula with SPME in rumen headspace
jar,with a tight cover,and placed in an ice cooler immediately after sampling.
Three rumen cannulated(101mm i.d.)Angus steers (868±49kg body weight)in individual(3.7m×12.6m) pens were fed27.2kg Fescue grass hay twice daily(8:00h and16:00h).The feed was weighed before each meal. Water was available ad libitum.All sampling was con-ducted on October9th–11th,2005,at the Iowa State University Beef Nutrition Center,Ames,Iowa,USA.The steers were individually restrained in a hydraulic chute during the SPME sampling.
Rumen gas samples were collected before morning feeding(9:00am)and two hours after feeding(1.00pm). For each animal the cannula stopper was replaced with the modified sampling device,which was fitted in the rumen cannula for5min before SPME sampling to enable rumen gases to reach equilibrium inside the headspace of the sampling device.During SPME extraction the septum fitted in the sampler was pierced by use of the SPME needle and the SPME fiber was exposed to the headspace for5min. These sampling times were selected on the basis of consideration of animal well-being and previous experience with restraining steers in hydraulic chutes[26].When SPME sampling was complete SPME fiber was enfolded in aluminium foil to be transferred to the Atmospheric Air Quality Laboratory at Iowa State University to be analyzed. The SPME fiber was desorbed for40min at260°C.The same sampling device,i.e.modified cannula plug was used for all three steers.Thorough rinsing with hot water,and air drying,were used to clean the device between applications. HS-SPME extraction of a blank device did not result in significant amounts of the target analytes selected for analysis.
Analysis of rumen gases
Multidimensional GC–MS–O(Microanalytics,Round Rock,TX,USA)was used for all analysis[27–29].The system integrates GC-O with conventional GC–MS analy-sis(Agilent,Wilmington,DE,USA;6890N GC and5973 MS)by addition of an olfactory port and a flame ionization detector(FID).The system was equipped with a non-polar precolumn and polar analytical column,in series,and system-automation and data-acquisition software(Multi-Trax V.6.00and AromaTrax V.6.61;Microanalytics and ChemStation,Agilent).The general conditions used were: injector temperature,260°C;FID temperature,280°C, column temperature,40°C for3min then programmed at 7°C min–1to220°C which was held for10min;carrier gas,He.The mass-to-charge ratio(m/z)range was set between33and280.Spectra were collected at six scans s?1 and the electron-multiplier potential was set to1200V.The MS detector was auto-tuned weekly.
The identity of compounds was verified by use of:
1.reference standards(Sigma–Aldrich,Fisher,Fluka)and
matching their retention times in multidimensional capillary GC and their mass spectra;
2.matching mass spectra of unknown compounds with
those in the BenchTop/PBM(Palisade Mass Spectrom-etry,Ithaca,NY,USA)MS library search system and with those of pure compounds;and
3.by matching the description of odor character.
Rumen gas was analyzed qualitatively only.Abundance in the gas was measured using area counts under peaks of characteristic single ions for the separated gases.The peak-area counts are reported for comparison only.One human panelist was used to sniff separated compounds simulta-neously with chemical analyses.Odor caused by separated gases was evaluated by use of a64-descriptor panel and intensity scale in Aromatrax software[27–29].Odor evaluations consisted of comparisons of:
1.the number of odor events;and
2.the total odor measured as the product of odor intensity
and odor event time length recorded in an aromagram.
Aromagrams were recorded by panelists,using the human nose as a detector.Odor events resulting from separated analytes eluting from the column were character-ized for odor descriptor and odor intensity.
Results and discussion
Effects of SPME extraction time on VOCs and odor
of rumen Gas
The effects of SPME extraction times of1min,5min (triplicate),and10min at a fixed temperature of39°C inside the headspace of the rumen,for selected compounds, are presented in Fig.2.The compounds selected were the main rumen fermentation products and also compounds which significantly contributed to the offensive odor of rumen gas.Odorous gases included most of the well known gases emitted from cattle and swine operations[28],e.g. VFAs,volatile sulfur compounds(VSCs),phenolic com-pounds,and indoles.The amount of each compound extracted by the SPME fiber increased with sampling time except for H2S.This might be because of the limited number of adsorption sites on the Carboxen–PDMS coating and possible competitive adsorption and displacement. Higher-MW compounds, e.g.semi-VOCs,can displace lower MW compounds as a consequence of competition for active sites on the fiber[25],particularly for complex matrices.This can be minimized when shorter extraction times are used[23,32].In this study,5min was selected for
all target compounds,because of the feasibility of restrain-ing the steer for a limited sampling time only.
The repeatability of in-vivo rumen gas sampling using the modified cannula/SPME port sampler was evaluated by comparing three replicate rumen gas samples.Average RSD for the compounds selected,except propanoic acid,was 26%.RSDs for octene isomers,phenolic compounds,indole,and alcohols were less than 20%.For both the VSCs and VFAs RSD was much greater (≥30%).For H 2S,3-methylthiophene,4-methylphenol,and indole RSDs were 19,13,18,and 16%,respectively.This is probably because of the relatively short sampling time and the dynamic nature of the rumen headspace.The dynamic nature of rumen gas was also implicated as a possible source of uncertainties by Dewhurst et al.[15].The effect of SPME extraction time on total odor and the total number of odor events in the series of aromagrams of rumen gas is shown in Fig.3.The total odor was estimated as the sum of the products (odor duration)×(odor intensity)for all the odor events in all time-series samples of rumen headspace.As is apparent from Fig.3,longer extraction times resulted in a significant increase in the total odor and the total number of odor events.
Sixteen characteristic odors that were most frequently present in rumen gas were selected for further evaluation of the effects of SPME sampling time on odor (Fig.4).These characteristic odors were correlated with corresponding compounds (Table 2).The data presented in Fig.4indicate that the odor intensity of most of the characteristic odors increased with longer sampling time.
10000
20000
30000
40000
Extraction time (min)
P a n e l i s t r e s p o n s e (t o t a l o d o r )
Fig.3Effect of time on HS-SPME extraction of the total odor of rumen gases,before feeding,at a fixed temperature of 39°C inside the cattle rumen,with an 85μm Carboxen –PDMS fiber.Extraction time=1min,5min (n =3),and 10min.Error bars signify the standard deviation of
the mean.The numbers signify total odor events for a sample
Fig.2Effect of time on HS-SPME extraction of 16compounds from rumen gases,before feeding,at a fixed tem-perature of 39°C inside the cattle rumen,with an 85μm Carboxen –PDMS fiber.Extrac-tion time=1min,5min (n =3),and 10min.Error bars signify the standard deviation of the mean.The numbers in paren-theses are the single ions from each compound used for peak-area count integration
Particularly noteworthy were “mushroom/moldy (1-octen-3-one)”and “taco shell (2′-aminoacetophenone)”.The presence of these odor-causing compounds could be easily overlooked in conventional analysis of MS chromato-grams,because they were present in rumen gas at very
low concentrations and the resulting MS detector responses were masked by the background signal.Only the use of a more sensitive detector (i.e.the human nose)and matching of aromagrams with total ion chromato-grams (TIC),possible with the GC –MS –O
approach,
Fig.4Effect of time on HS-SPME extraction of 19charac-teristic odors from rumen gases,before feeding,at a fixed tem-perature 39°C inside the cattle rumen,with an 85-μm Car-boxen –PDMS fiber.Extraction time=1min,5min (n =3),and 10min.Error bars signify the standard deviations of the means
Table 2Summary of compounds identified in rumen gas No Retention time Compound
CAS MW Odor threshold h (ppm)Odor character 1*1.20H 2S
7783-06-434.080.01778Sewer 2 1.41cis-1,2-Dimethyl cyclopropane 930-18-770.14n/a Sweet 3 1.532-methyl-1-butene 563-46-270.14n/a
4*1.68Ethanethiol
75-08-162.130.001072Foul,fecal 5*1.70Dimethyl sulfide a 75-18-362.130.002239Onion,garlic
6*1.801-Propanethiol 107-03-976.160.0012597*1.932-Propanone a 67-64-158.0814.458 2.153-Hexyne 928-49-482.15n/a 9*2.712-Butanone 78-93-372.117.76210 3.502-Nitro pyridine 15009-91-3124.1n/a
11 3.962,4-Hexadienal 142-83-696.130.000549512*4.112-Pentanone 107-87-986.14 1.549Ketone
13*4.36Octane 111-65-9114.2 5.75414*4.764-Octene 7642-15-1112.2n/a 15*4.563-Octene 14919-01-8112.2n/a
16*4.482-Octene
111-67-1112.20.0758617*5.66Methylbenzene b
108-88-392.14 1.549Ketone 18*5.88Dimethyl disulfide b 624-92-094.20.0123Sulfury 19*6.412-Pentanol
6032-29-788.15n/a 20*6.503-methyl thiophene 616-44-498.17n/a Sulfury,skunky
21*7.03Nonane
111-84-2128.3 1.259228.082,6-dimethyl-1,7-Octadiene 6874-35-7138.1n/a 238.213-Nonyne 20184-89-8124.2n/a 24*8.25Alpha-pinene
80-56-8136.20.6918Ketone 258.633,7-Dimethyl-octa-1,6-diene –
138.1n/a Moldy 26*8.88Camphene
79-92-5136.2n/a 279.032,6-Dimethyl-2-octene 4057-42-5140.3n/a Sweet
28
9.71
Sabinene
3387-41-5
136.2
n/a
enabled us to identify those compounds.We were able to identify them only because of their significant odor intensity and the characteristic odor perceived by an olfactometry panelist.Both1-octen-3-one and2′-amino-acetophenone are very potent odorants.The odor detection threshold in air(ODT air)for1-octen-3-one is 0.03–1.12ng L?1[33].ODT air for2-aminoacetophenone is not published,but its ODT in water(ODT water)is0.2μg L?1[33].
Identification of VOCs in rumen headspace
Rumen gas samples were analyzed by multidimensional GC–MS–O,which enabled simultaneous identification and analysis of chemicals and corresponding odors and collec-tion of a chromatogram and https://www.wendangku.net/doc/fc11499882.html,parison of a typical chromatogram(lower,red line)and aromagram (upper,black line)of rumen gas after feeding is shown in Fig.5.A variety of compounds with wide range of odor characteristics were found.The total-ion chromatogram typically had a complex peak/compound pattern.The50 compounds with the most prominent peaks are listed in Table2.These compounds are typical rumen fermentation products,for example VFAs and VSCs,which have been reported in the literature[15].The aromagram(upper,black line in Fig.2)showed that as many as38distinct odors were recorded in rumen gas.Most of the odors detected in rumen gas were perceived as offensive(Table2).
Fifty VOCs belonging to ten chemical groups were identified in rumen gas:sulfides and thiols(8),VFAs(7), ketones(4),alkanes(14),alcohols(2),phenolic compounds (4),benzene derivatives(3),nitrogen heterocycles(3), aldehydes(1),and monoterpenes(4).Of these,37have not previously been reported in studies of rumen fluid and gases[9–12,15–17,33](Table2).It is interesting to note that the chemical compound groups identified in this study were similar to those found previously in ambient air at a dairy farm[34],except for VSCs.One new chemical group found in rumen gas in this study was monoterpenes.Four monoterpenes includingα-pinene,camphene,sabinene,
No Retention time Compound CAS MW Odor threshold h(ppm)Odor character 2910.683-Ethyl-2,5-dimethyl-1,3-Hexadiene62338-07-2138.1n/a
3010.911-Methyl-4-[1-methylethyl]cyclohexene1195-31-9138.3n/a
31*11.33Limonene138-86-3136.20.4365
3211.881-Methyl-4-[1-methylethyl]benzene99-87-6134.2n/a
3312.01[2Z]-8-Methyl-2,7-nonadien-4-one89780-46-1152.1n/a
34*12.56Dimethyl trisulfide3658-80-81260.00166Onion,garlic
35*13.03Acetic acid a,b,c,d,e,g64-19-760.050.1445Acidic
3613.682-Butyl naphthalene1134-62-9184.3n/a
37*14.482-Ethyl-1-hexanol104-76-7130.20.2455
38*14.65Propanoic acid a,b,c,d,e,g79-09-474.080.03548Burnt,burnt food 39*15.18Dimethyl propanedioic acid595-46-0132.1n/a Burnt
40*16.28Butanoic acid a,b,c,d,e,g107-92-688.110.00389Burnt,body odor 41*17.003-Methyl butanoic acid b,c,d,e,g503-74-2102.10.002455Burnt,body odor 42*18.18Pentanoic acid a,b,c,d,e109-52-4102.10.03715Burnt,body odor 43*19.98Hexanoic acid a,b,c,d142-62-1116.20.01259Fatty acid
44*20.95Dimethyl sulfone67-71-094.1n/a Burnt
45*22.51Phenol108-95-294.110.1096Medicinal,phenolic 46*23.634-Methyl phenol106-44-5108.10.1096Barnyard,urious 47*25.014-Ethyl phenol620-17-7122.20.001862Barnyard,phenolic 48*26.283-Propyl phenol621-27-2136.2n/a Phenolic
49*28.65Indole f120-72-9117.20.000032Barnyard
50*29.26Skatole f83-34-1131.20.000562Naphthalenic
a Dewhurst,et al.[15]
b Spinhirne,et al.[16]
c Schneider,et al.[17]
d Teunissen,et al.[9]
e Faichney,et al.[10]
f Williams,et al.[11]
g Calabro,et al.[2]
h Devos,et al.[33]
*Confirmed with authentic standards.
n/a=not available
Table2(continued)
and limonene were identified in the gas.Sunesson et al.[34]reported that monoterpenes were found in the ambient air of a dairy farm and attributed this mainly to the sawdust used for bedding.Wood is a well known source of monoterpenes.This study reveals the monoterpenes could be arising from other sources (e.g.,Fescue grass in the feed)[35].Thus,eructated rumen gas could be another potential source of monoterpenes in ambient air in and around cattle feedlots and possibly dairies.More research is needed to confirm this hypothesis.Rabaud et al.[36]reported that the vast majority of compounds emitted from a commercial dairy,for example VFAs,alcohols,aldehydes,and ketones resulted from carbohydrate oxidation and fermentation during and after digestion.
The identities of thirty-five out of the 50compounds found in this study were confirmed by use of the retention times and spectra of authentic standard compounds (Table 2).The others were identified by use of the BenchTop/PBM mass spectrometry library search system (match above 70%)and by matching their known odor character [37].The VOCs identified had a wide range of molecular weight (MW)(34to 184),boiling point (?63.3to 292°C),vapor pressure (1.05×10?5to 1.17×102Pa)and water solubility (0.66to 1×106mg L ?1).As many as 22compounds had published ODT below 1ppm [33].Four compounds including 2-butanone,toluene,phenol,and p -cresol are classified as HAPs [38].As many as 54%of the compounds had estimated atmospheric lifetimes <24h,
on the basis of reaction with OH radicals.Estimating actual emissions of reactive organic compounds from rumen gases could be useful in emission inventories for protected airsheds with a large cattle https://www.wendangku.net/doc/fc11499882.html,parison of rumen gases before and after feeding The feasibility of rapid testing of rumen gas by SPME to elucidate useful information related to digestion was demonstrated by sampling before and after feeding.Twelve odorous gases,including the well known gases emitted from manure —VFAs,VSCs,phenolic compounds,and skatole —were then selected for further comparisons.A qualitative comparison of the 12rumen gas compounds before and after feeding for three animals on 3days is shown in Fig.6.C 2–C 6short-chain fatty acids were identified,including acetic acid,propanoic acid,butanoic acid,3-methylbutanoic acid,pentanoic acid,and hexanoic acid.V olatile fatty acids are the main products of bacterial fermentation in the rumen and are absorbed through the rumen wall into the blood stream and form the primary energy source for the host animal [39].Low-molecular-weight VFAs have been used to determine the energy efficiency of microbial fermentation in the ruminant [16].Many researchers believe that C 2to C 9VFAs are the most important odor indicators of all the volatile organic compounds (VOCs)found in agricultural air [40,41].The relative abundance of all the VFAs in rumen gas was
higher
Fig.5Total ion chromatogram (TIC)(lower line )and aromagram (upper line )obtained from rumen gas after feeding.Samples were collected by use of a Carboxen –PDMS 85μm SPME fiber and a 5min in-vivo rumen sampling time
after feeding than before.This could be because of the pH of the rumen fluid,which is very responsive to meals and chewing behavior;ruminal pH decreases rapidly after meals and increases rapidly during rumination [42].At the lower ruminal pH after feeding a greater fraction of the VFAs has been observed in the associated form in rumen fluid,so the concentration of VFAs in rumen gas would probably increase.Dewhurst et al.[15]observed that the relative concentrations of VFAs in rumen gas and rumen fluid decreased with increasing chain length.In addition,the overall molar proportions of the VFAs were very similar in rumen fluid and rumen gas [15].
The apparent amounts of dimethyl sulfide,dimethyl disulfide,and dimethyl trisulfide in rumen gas after feeding
were much higher than before feeding.The amount of dimethyl sulfide after feeding was more than ten times that before feeding.These observations are consistent with previous reports of the substantial amounts of dimethyl sulfide produced by the rumen [43,44]and consistent with higher levels of dimethyl sulfide production immediately after feeding [45].It is worthy of note that dimethyl sulfide (DMS)is an inverse “greenhouse effect ”gas [45,46]and may be released to the atmosphere by cattle eructation.VFAs and VSCs,phenol,4-ethylphenol,and skatole were also present in greater amounts in rumen gas after feeding.Although these preliminary observations are generally consistent with literature reports,they have limited statis-tical significance only,because of the relatively
small
Fig.7Differences between to-tal odor and characteristic odors of rumen gases before and after feeding of three steers.Error bars signify the positive stan-dard deviation of the
mean
Fig.6Comparison of the peak area counts of 12charac-teristic compounds in rumen gas before and after feeding for three steers.Samples were col-lected by use of an 85-μm Carboxen –PDMS SPME fiber.Extraction time=5min.Error bars signify the standard devia-tions of the means.The numbers in parentheses are the single ions from each compound used for peak-area count integration.Asterisks indicate significant differences between before and after feeding
number of replicates(3steers and3days).Only for phenol were the amounts before and after feeding significantly different(P-value=0.0391).
Figure7shows differences between total odor and between characteristic odors for rumen gas samples collected before and after feeding from three animals on three days.There were no significant differences between the total odors,measured by GC–O,of rumen gas before and after feeding(P-value=0.9293).Differences detected between the characteristic odors were,however,consistent with the specific compounds discussed above.The odor intensity of rumen gas caused by VFAs and VSCs after feeding was greater than that before feeding.One of the characteristic odors,i.e.“onion,foul”(caused by dimethyl sulfide)was significantly different(P-value=0.0049)which is consistent with the increase of dimethyl sulfide in the rumen headspace(P-value=0.0867).
More research is needed to quantify the gases in rumen headspace and to determine rumen liquid–gas correlations related to digestion.Rumen gases reflect the processes of fermentation within the entire reticulo–rumen system.Thus, in-vivo sampling of rumen gases may overcome some of the sampling challenges related to compartmentalization and variation across the rumen[3].Information about rumen gases can potentially be used to assess the extent of digestion of feed in the rumen[2,15]and to diagnose disease or rumen disfunction.
Conclusions
Several conclusions can be made from this study:
1.The new device proved useful for in-vivo rumen-gas
collection by SPME under field conditions.Sampling times as long as10min were practical.Longer extraction times may be possible with free-range steers if the septum port is protected.
2.SPME-GC–MS–O can be a useful technique for
monitoring feed digestion in-vivo and for observing the relationship between feed and odor/VOC emissions from beef cattle operations.
3.Rumen gas contains at least50VOCs belonging to ten
chemical groups.In this research the identities of34were confirmed by use of pure standards.The compounds identified had a wide range of MW,boiling point,vapor pressure,and water solubility.A new chemical group,the monoterpenes,was found in rumen gas.
4.Many of the most offensive and characteristic odorants
associated with livestock production were found in rumen gas.Odorous compounds included those emitted from manure,for example VFAs,VSCs,phenolic compounds,and indoles.As many as22compounds
had an ODT<1ppm.These results indicate that rumen gases could be a source of aerial emissions and odor.
Alteration of the rumen environment could have potential implications in odor control.
5.More than half the rumen gas compounds identified in
this research are reactive and have an estimated atmospheric lifetime of<24h.It has been suggested that at least one of these compounds(dimethyl sulfide) is an inverse“greenhouse effect”gas.More research is warranted to determine actual concentrations and emissions of these rumen gases to the atmosphere, because they may be important sources of odor in areas with large cattle populations.
Acknowledgements This project was sponsored in part by Iowa State University and the Iowa Beef Center.The assistance of Rod Berryman,Kelly Nissen,Jeff Thorsen,Kevin Twedt and Dave Fisher of the ISU Beef Nutrition Center is greatly appreciated. References
1.Church DC(ed)(1988)The ruminant animal.Prentice–Hall,
Englewood Cliffs,NJ
2.Calabro S,Lopez S,Piccolo V,Dijkstra J,Dhanoa MS,France J
(2005)Anim Feed Sci Technol123–124:51–65
3.Dirksen GU,Smith MC(1987)Bovine Pract22:108–116
4.Garrett EF,Pereira MN,Nordlund KV,Armentano LE,Goodger
WJ,Oetzel GR(1999)J Dairy Sci82:1170–1178
5.Hungate RE(1996)The rumen and its microbes.Academic Press,
New York
6.Erlich GG,Goerlitz DF,Bourell JH,Eisen GV,Godsy EM(1981)
Appl Environ Microbiol42:878–885
7.Brotz PG,Schaefer DM(1987)J Microbiol Methods6:139–144
8.Ziolecki A,Kwiatkowska E(1973)J Chromatogr80:250–254
9.Teunissen MJ,Marras SAE,Op den Camp HJM,V ogels GD
(1989)J Microbiol Methods10:247–254
10.Faichney GJ(1967)J Chromatogr27:482–484
11.Williams GD,Rippon P,Chen P,Camp BJ(1979)Anal Biochem
99:324–331
12.Phillips KD,Tearle PV,Willis AT(1976)J Clin Pathol29:22–27
13.Brooks JB,Moore WEC(1969)Can J Microbiol15:143–147
14.Salanitro JP,Muirhead PA(1975)Appl Microbiol29:374–381
15.Dewhurst RJ,Evans RT,Mottram TT,Spanel P,Smith D(2001)
J Dairy Sci84:1438–1444
16.Spinhirne JP,Koziel JA,Chirase NK(2003)Trans ASAE46:585–588
17.Schneider IC,Ames ML,Rasmussen MA,Reilly PJ(2002)J Agric
Food Chem50:2267–2273
18.Koziel JA,Spinhirne JP,Lloyd J,Parker D,Wright D,Kuhrt F
(2005)J Air Waste Manage Assoc55:1147–1157
19.Keener KM,Zhang J,Bottcher RW,Munilla RD(2002)Trans
ASAE45:1579–1584
20.Huebner MA,Hoff SJ,Zelle BC,Gralapp AK(2005)Paper05-A-
1067-AWMA in the Proceedings of the AWMA Annual Confer-ence and Exhibition,Minneapolis
21.Koziel JA,Noah J,and Pawliszyn J(2001)Environ Sci Technol
35:1481–1486
22.Pawliszyn J(1999)(eds)Applications of Solid Phase Micro-
extraction,The Royal Society of Chemistry,Hertfordshire,UK 23.Koziel JA,Pawliszyn J(2001)J Air Waste Manage Assoc
51:173–184
24.Gorecki T,In:Pawliszyn J(eds)(1999)Applications of Solid
Phase Microextraction,Royal Society of Chemistry,Cambridge
25.Koziel JA,Jia M,Pawliszyn J(2000)Anal Chem72:5178–5186
26.Spinhirne JP,Koziel JA,Chirase N(2004)J Chromatogr A
1025:63–69
27.Cai L,Koziel JA,Lo YC,Hoff SJ(2006)J Chromatogr A
1102:60–72
28.Wright D,Nielsen L,Eaton D,Kuhrt F,Koziel JA,Spinhirne JP,
Parker DB(2005)J Agric Food Chem53:8663–8672
29.Koziel JA,Cai L,Wright D,Hoff S(2006)J Chromatogr Sci
44:451–457
30.Haberhauer-Troyer C,Rosenberg E,Grasserbauer M(1999)
J Chromatogr A48:305–315
31.Pan L,Adams M,Pawliszyn J(1995)Anal Chem67:4396–4402
32.Augusto F,Koziel JA,Pawliszyn J(2001)Anal Chem73:481–486
33.Devos M,Patte F,Roualt J,Laffort P,Van Gemert LJ(eds)(1990)
Standardized Human Olfactory Thresholds,IRL Press at Oxford Press,NY,New York
34.Sunesson AL,Gullberg J,Blomquist G(2001)J Environ Monit
3:210–21635.Fukui Y,Doskey PV(2000)Atmos Environ34:2947–2956
36.Rabaud NE,Ebeler SE,Ashbaugh LL,Flocchini RG(2003)
Atmos Environ37:933–940
37.Flavornet.https://www.wendangku.net/doc/fc11499882.html,/flavornet.html accessed on
June22,2006
38.Air Pollution Engineering Manual,Davis WT(eds)(2000)Wiley,
New York
39.Barnes RF,Nelson CJ,Collins M,Moore KJ(eds)(2003)
Forages,6th edn.Blackwell,Ames,Iowa
40.Zhu J(1999)Trans ASAE42:175–182
41.Wiles M,Elwell D,Keener H,Amburgey J,Borger D,Willett L
(2000)Compost Sci Util9:27–37
42.Allen MS(1997)J Dairy Sci80:1447–1462
43.Mottram TT,Ditcham WJF,Bolam H,Short L,Cammell S,Beever
DE,Hobbs PJ(2000)Silsoe Research Institute,Bedfordshire,UK 44.Williams J,Wang N,Cicerone RJ,Yagi K,Kurihara M,Terada F
(1999)Glob Biogeochem Cycl13:485–491
45.Bates TS,Charlson RJ,Gammon RH(1987)Nature329:319–321
46.Charlson RJ,Lovelock JE,Andrea MO,Warren SG(1987)Nature
326:655–661
铜转炉白烟尘加压浸出工艺研究
doi：10.3969/j.issn.1007-7545.2018.04.002 铜转炉白烟尘加压浸出工艺研究 刘飞1,2，洪育民1，赵磊2 （1.江西铜业集团公司贵溪冶炼厂，江西贵溪335424；2.北京矿冶科技集团有限公司，北京100160) 摘要：针对铜冶炼转炉白烟尘中有价金属的综合利用，开展了加压浸出工艺研究。在液固比6︰1(mL/g)、初始硫酸浓度0.6 mol/L、浸出温度120 ℃、氧分压0.6 MPa、浸出时间3 h、搅拌速度500 r/min的条件下，Cu、Zn 浸出率均高于95%，Cd浸出率大于90%，As、Fe浸出率可以控制在10%以下。同步实现Cu、Zn、Cd高效浸出与As、Fe的抑制，有利于后续加压浸出液中的有价金属的分离。 关键词：白烟尘；加压浸出；铜；砷；铁 中图分类号：TF811 文献标志码：A 文章编号：1007-7545（2018）04-0000-00 Study on Pressure Leaching of Copper Converter White Dust LIU Fei1,2, HONG Yu-min1, ZHAO Lei2 (1.Guixi Smelter, Jiangxi Copper Corporation, Guixi 335424, Jiangxi, China; 2. BGRIMM Technology Group, Beijing 100160, China) Abstract：To realize comprehensive utilization of valuable metals in copper converter white dust, pressure leaching process was carried out. The results show that leaching rate of metals is Cu>95%, Zn>95%, Cd>90%, As<10%, Fe<10% under the optimum conditions including L/S of 6︰1(mg/L), initial sulfuric acid concentration of 0.6 mol/L, leaching temperature of 120 ℃, oxygen partial pressure of 0.6 MPa, leaching time of 3 h, and stirring speed of 500 r/min. Valuable elements of copper, zinc and cadmium can be effectively separated from impurities of arsenic and iron which facilitates separation of valuable metals in lixivium. Key words：white dust; pressure leaching; copper; arsenic; iron 国内大型铜冶炼厂多通过闪速熔炼、PS转炉吹炼和回转式阳极炉精炼等工序将铜精矿和废杂铜冶炼成能满足电解精炼工序需求的阳极板。在冶炼过程中，入炉物料含有的微量Pb、Zn、As、Sb、Bi、Cd、In等元素在转炉白烟尘（以下简称白烟尘）中得到了富集。白烟尘的处理工艺以湿法提取为主，其中硫酸体系浸出又占主流地位，如铜陵有色、金川公司、云南铜业、方圆铜业和中条山有色等企业均采用类似工艺[1-3]。硫酸体系浸出的本质是利用Pb、Bi及其化合物几乎不溶于稀硫酸溶液的特性，通过浸出实现Pb、Bi与Cu、Zn、In、Cd等金属的分离[4-6]。但对于含有较多硫化物、低价氧化物和复杂盐类化合物等成分复杂的白烟尘，采用常规硫酸体系浸出效果不是很理想，铜的浸出率不高，约75%，而且大量As、Fe等杂质元素进入浸出液（As浸出率~60%，Fe浸出率50%），加大了浸出液处理难度，拉长了工艺流程。 加压浸出是高温高压下强化浸出过程，同时利用氧气或空气中氧气对物料中的硫化物、低价氧化物进行氧化，可以有效提高元素浸出率，缩短浸出时间[7]，在镍精矿、锌精矿、钼精矿、钨精矿、金精矿以及砷滤饼获得大规模的工业推广应用，但在白烟尘处理上尚未有应用。徐志峰等[8]开展了高铜高砷白烟尘的加压浸出研究，在液固比5︰1(mL/g)、初始硫酸浓度0.74 mol/L、浸出温度180 ℃、氧分压0.7 MPa、浸出时间2 h的条件下，Cu、Zn浸出率分别约95％和99％，As浸出率约20％，Fe浸出率仅6％左右，实现了Cu、Zn与As、Fe较好的分离。但在浸出温度180 ℃时，蒸汽分压1.0 MPa，再加上氧分压0.7 MPa，总压达到了1.7 MPa。过高的温度和压力一方面会增加设备投资成本和生产运营成本；另一方面，氧分压过高，不利于安全生产，设备材质选择上也需要单独考虑。因此，本研究以国内某大型铜冶炼厂白烟尘为原料，并结合该企业需求及现有工艺流程，探索较低温度、较低压力下白烟尘的高效浸出分离技术。 1 试验原料及研究方法 试验所用白烟尘的化学成分（%）：Cu 14.52、Pb 17.31、Zn 4.34、As 6.51、Fe 4.42、Bi 6.66、Cd 1.55、S 9.29。其中，铜的物相组成为（%）：硫酸铜25.46、硫化铜30.27、氧化铜12.37、氧化亚铜15.61、其他16.29。 收稿日期：2017-10-17 基金项目：国家高技术研究发展计划(863计划)项目(2013AA064002) 作者简介：刘飞（1980-），男，江苏泗洪人，工学硕士，高级工程师.
铜冶炼厂的危险因素辨识与控制
2.4.1 产品方案和设计规模 2.4.1.1 设计规模 本项目规模为：金铜混合精矿处理能力150万t/a。 2.4.1.2 产品方案 产品方案为金锭、银锭、硫酸镍、粗硒、1号标准铜、2号标准铜和硫酸，主要产品为： （1）金锭：57.70t/a 含Au≥99.99% 产品质量符合GB/T4134-2003 1号金国家标准 （2）银锭：190.77t/a 含Ag≥99.99% 产品质量符合GB/T4135-2002 1号银国家标准。 （3）精硒: 21.50t/a，含Se 99.99%。 （4）粗碲：18.20t/a，含Te 98%。 （5）A级铜：92800t/a，含Cu 99.9935% 产品质量符合GB/T467-2010 Cu-CATH-1国家标准。
（6）1号标准铜：1664t/a，含Cu 99.95% 产品质量符合GB/T467-2010 中Cu-CATH-2国家标准，送成品库。 （7）粗硫酸镍：520t/a，含Ni18%。 2.4.2 主要技术方案及生产工艺流程 火法工艺流程为：精矿富氧底吹熔炼—铜锍旋浮吹炼—粗铜回转式阳极炉精炼—不锈钢永久阴极电解，铜阳极泥浸出渣采用氧气斜吹旋转转炉熔炼。 铜电解采用大板不锈钢永久阴极电解工艺，产品为A级铜。净液采用传统电积和旋流电积相结合的工艺生产1号标准铜、黑铜。阳极泥处理结合湿法和火法流程的优点，采用加压浸出—合金吹炼炉工艺。 富氧底吹熔池熔炼属富氧强化熔炼技术，富氧底吹熔池熔炼炼铜技术近几年逐渐发展起来，工业化技术已经成熟。熔炼炉炼铜工艺作为我国自主开发的炼铜工艺，经过越南生权、山东东营、山东恒邦以
行业标准-《铜冶炼烟尘化学分析方法 第7部分》-送审稿(编制说明)
铜冶炼烟尘化学分析方法第7部分：镉量的测定 火焰原子吸收光谱法和容量法 编制说明 铜陵有色金属集团控股有限公司、北矿检测技术有限公司 2020年9月
铜冶炼烟尘化学分析方法 第7部分：镉量的测定火焰原子吸收光谱法和容量法 编制说明 一、工作简况 1.1方法概况 1.1.1项目的必要性 铜冶炼工业资源消耗大，二次资源综合利用率较低，有相当大部分可利用资源变成污染物。铜烟尘在铜冶金工业中排放量较大，至今没有得到充分的利用。铜冶炼烟尘属于高温烟灰，粒度较小，根据熔炼工艺以及收尘设备的不同，主要可分为奥炉烟灰、转炉烟灰、阳极烟灰、环集烟灰、奥炉开路烟灰、电收尘烟灰等。采用LS800型OMEC激光粒度测试仪分别对“铜烟灰”进行分析，“铜烟灰”的平均粒径（D50）为1.63μm 至2.31μm，颗粒小，露天堆放时，在雨水作用下，其铅/锌离子易渗入地下，造成环境污染。美国环境保护署在新制定的环境资源保护及回收法中，将其划归为KO61类物质(有毒的固体废物) , 要求冶炼厂对其中的锌、铅等有价元素进行回收处理或钝化处理；否则，须将其密封堆放在由专人监管的山谷中。在我国随着资源的日益枯竭和环保压力的增加，对冶炼烟尘回收已有较成熟的工艺。当前国内外处理铜冶炼烟尘主要有火法、火法-湿法联合法、全湿法、矿冶联合法等。 镉是银白色有光泽的金属，其在潮湿的空气中缓慢氧化并失去金属光泽，加热时表面形成棕色的氧化物层。镉的毒性较大，被镉污染的空气和食物对人体危害严重，日本因镉中毒曽出现“痛痛病”。镉作为烟尘中的有害元素，比其它重金属更容易被农作物所吸附。相当数量的镉通过空气、废尘、废水、废渣排入环境，造成污染。当环境受到镉污染后，镉可在生物体内富集，通过食物链进入人体引起慢性中毒。但其可用于电镀、执照高性能电池、生产颜料和荧光粉等。 从废弃物当中回收镉不仅可满足市场的供求关系，同时具有重大的战略意义。因此，制定铜冶炼烟尘中镉量测定方法，不但给冶炼厂带来良好的经济效益，对资源再生利用提供技术支撑，同时也规范了实验室检验过程，满足市场的需求。 1.1.2适用范围 本部分适用于铜冶炼烟尘中镉含量的测定。方法1火焰原子吸收光谱法测定范围：0.020%~5.00%；方法2 容量法测定范围：5.00%～17.00%。 1.1.3可行性 铜陵有色金属集团控股有限公司检测研究中心拥有CMA、CAL省级资质认定和CNAS国家实验室认可三个资质，属于面向社会服务第三方专业检测机构。主持和参与100多项国家、行业标准的起草工作；拥有丰富工作经验的技术人员和科研团队，具有较强的检测分析操作经验和深入的标准研究能力，拥有制定该方法必需的环境、设备。标准研制人员已参加过国家和行业标准制定的培训，熟料掌握标准制定规则，有利于资料整理、归纳及标准编制。 北矿检测技术有限公司为国家重有色金属质量监督检验中心、国家进出口商品检验有色金属认可实验室、中国有色金属工业重金属质检中心、科技成果检测鉴定国家级检测机构，在国内有色金属分析领域具有权威地位。公司拥有多台原子吸收光谱仪，具备项目研究所需的仪器设备。标准起草人员主起草国家行业标准多项，参与国家行业标准几十项，具有丰富的方法研究经验。 目前，国内铜冶炼企业烟尘的年产量在20万吨以上，其中仅铜陵有色金属集团控股有限公司就年产2万吨。铜烟尘中镉含量较高，若不对其进行有效的处理，其产生的环境危害要远大于其带来的经济效益本身。部分铜烟灰由各冶炼厂直接入炉熔炼，部分已经开始作为二次原料进入贸易市场。这样一来，实现既增加经济效益，又保护环境的“双赢”局面。随着环境压力和环保要求的提高，对回收利用单位资质要求越来越严，没有资质的公司纷纷将其出售，铜冶炼烟尘的贸易越来越频繁，仅广东一地的交易量一年就上万吨。 准确检测出铜冶炼烟尘中镉的含量，对企业确定回收工艺、提高烟尘的综合利用率并减轻对环境的污
基于过程强化的铜冶炼烟灰中砷选择性去除工艺及机理
基于过程强化的铜冶炼烟灰中砷选择性去除工艺及机理 我国是世界第一大铜生产和消费国,在矿产资源开采、运输和选冶过程中,会产生大量含重金属固体废弃物,与开采及尾矿处理过程产生的烟尘相比,冶炼过程中产生的烟灰粒径较小（≤0.1μm）、比表面积较大,不仅可进行长距离的迁移造成区域性污染,而且易通过呼吸系统被人体吸收,从而对生态环境产生更大的危害;另外,有色金属矿物冶炼被IPCS认定为最重要的砷排放点源之一,据统计,全球大气中的砷约40%来自于冶炼过程,其中铜矿冶炼排放量占80%。因此,从环境保护的角度,冶炼烟灰中砷的脱除及稳定化对于全球砷污染的控制具有积极意义。从地球资源角度,冶炼烟尘除含有大量Cu、Pb、Zn等金属外,还含有大量稀贵金属,如In、Ge、Ga等,相对日渐贫乏的精矿品味,烟尘中的有价金属含量甚至超过很多富矿,可作为十分珍贵的金属资源。然而,杂质砷的大量存在不仅增加资源化过程的负担,而且影响所产金属质量,已成为此类烟灰资源化的主要限制因素。随着铜精矿进一步匮乏,冶炼过程中产生固体废弃物（炉渣、烟尘等）必将成为“再生铜”资源重要组成部分,而如何实现此类材料中有价金属高效资源化已成为湿法冶金领域重要研究课题之一。目前,针对冶炼废弃物中有价金属元素资源化,大部分研究仍聚焦于有价金属元素湿法冶金技术的开发及机理,然而,与其他金属化合物相比,含As化合物热力学稳定性较低,易溶解于强酸、强碱等常用浸出剂。冶炼烟灰常与铜矿等制样后返回熔炼炉,但随着铜矿资源的锐减,高砷铜由砷化
合物具,矿的广泛使用必将导致冶炼烟灰中砷含量的持续增大． 有较高反应活性,因此极易进入后续分离工序,致使阴极铜质量下降。鉴于此,开发选择性浸出技术对烟灰进行脱砷预处理后再熔炼对其资源化具有积极意义。NaOH-Na2S复合浸出体系理论上可选择性除砷,但仍存在药剂消耗量大、耗时长、浸出率低等缺点,并且随着烟灰中砷含量增高,这种缺点则越突出。考虑到烟灰中砷和其它金属的价态和存在形式等是决定其浸出率的主要控制因素,因此,准 确确定砷及其它金属在烟尘颗粒内部的赋存状态是开发强化浸出技 术的首要问题;另外,仍缺乏从微观水平上NaOH、Na2S等药剂浸出砷各自作用机理及其协同作用机制。为此,本文以铜冶炼澳炉烟灰为研究对象,在分析烟灰组成成分、物相、形貌分析所用烟灰ANC\BNC等特征基础上,对比研究了水洗预处理前后烟灰中有价金属元素（Cu、Zn、Bi、Sn、Mo、Sb、Ba、Al等）及有毒有害金属元素（Pb、Ni、As、Cd、Co等）浸出特性并构建了烟灰中重金属赋存状态与其浸出特性之间关系,揭示了溶解-沉控制机制、吸附-解吸控制机制、传质控制机制对其浸出作用规律各金属元素在不同pH条件下浸出机理及主要控制因素;为了开发符合清洁生产标准的高效脱砷技术,确定了微波、超声、球磨三种新型辅助浸出技术对As在 NaOH-Na2S浸出体系分离浸出效率,并从微观尺度上揭示了NaOH、Na2S浸出砷作用机制。论文的主要工作及结论如下:（1）从热力学角度构建了烟灰中重金属赋存状态与其浸出特性之间关系,揭示了溶解-沉控制机制、吸附-解吸控制机制、传质控制、
铜闪速熔炼烟灰浸出试验研究
Metallurgical Engineering 冶金工程, 2015, 2(3), 151-157 Published Online September 2015 in Hans. https://www.wendangku.net/doc/fc11499882.html,/journal/meng https://www.wendangku.net/doc/fc11499882.html,/10.12677/meng.2015.23022 Study on Leaching of Dust of Copper Flash Smelting Furnace Yan Wen Tong Ling Nonferrous Metals Group Holding Co., Ltd., Tongling Anhui Email: weny@https://www.wendangku.net/doc/fc11499882.html, Received: Aug. 20th, 2015; accepted: Sep. 10th, 2015; published: Sep. 16th, 2015 Copyright ? 2015 by author and Hans Publishers Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). https://www.wendangku.net/doc/fc11499882.html,/licenses/by/4.0/ Abstract The influence of initial concentration of sulfuric acid, leaching temperature, leaching time and liquid-solid ratio on the dust of the flash smelting furnace was investigated. And the structure of the dust of the flash smelting furnace and leaching slag was characterized by X-ray diffrac-tion (XRD). Results showed that the chemical forms of copper in the dust of the flash smelting furnace are mainly copper sulfate and copper ferrite. The copper sulfate is water-soluble, while the copper ferrite is difficult to leach even under high concentration of acid and high tempera-ture. What’s more, it is found that the initial concentration of sulfuric acid, leaching tempera-ture and leaching time have limited influence on the leaching efficiency of copper, iron, arsenic and zinc. Keywords Dust of Flash Smelting Furnace, Sulphating Leaching, Cu, Fe, As 铜闪速熔炼烟灰浸出试验研究 文燕 铜陵有色金属集团股份有限公司，安徽铜陵 Email: weny@https://www.wendangku.net/doc/fc11499882.html, 收稿日期：2015年8月20日；录用日期：2015年9月10日；发布日期：2015年9月16日
行业标准-《铜冶炼烟尘化学分析方法 第9部分》-送审稿(编制说明)
铜冶炼烟尘化学分析方法 第9部分：锑含量的测定火焰原子吸收光谱法 编制说明 铜陵有色金属集团控股有限公司 2020.9
中华人民共和国有色金属行业标准 铜冶炼烟尘化学分析方法 第9部分：锑含量的测定火焰原子吸收光谱法 编制说明 (计划编号：工信厅科【2018】31号2018-0535T-YS ) 一：工作简况 1.1 方法概况 1.1.1、项目的必要性 在我国随着资源的日益枯竭和环保压力的增加，对冶炼烟尘回收已有较成熟的工艺。铜冶炼烟尘属于高温烟灰，粒度较小，根据熔炼工艺以及收尘设备的不同，主要可分为奥炉烟灰、转炉烟灰、阳极烟灰、环集烟灰、奥炉开路烟灰、电收尘烟灰等。当前,国内外处理铜冶炼烟尘主要有火法、火法-湿法联合法、全湿法、矿冶联合法等。 铜冶炼工业资源消耗大，二次资源综合利用率较低，有相当大部分可利用资源变成污染物。铜烟尘在铜冶金工业中排放量较大。随着环境压力和环保要求的提高，铜冶炼烟尘的贸易越来越频繁，准确检测出铜冶炼烟尘中锑的含量，对企业确定回收工艺、提高烟尘的综合利用率并减轻对环境的污染及进行贸易的双方都有着巨大的推动作用。 锑是一种银白色有光泽硬而脆的金属，在潮湿空气中逐渐失去金属光泽，强热则燃烧成白色锑的氧化物。锑作为全球性的污染物，是目前国际上最为关注的有毒金属元素之一。根据《中华人民共和国国家标准污水综合排放标准》，锑（Sb）属于第一类污染物,其最高允许排放浓度为0.1mg/L。欧盟将锑列为高危害有毒物质和可致癌物质并予以规管。锑大部分用于生产阻燃剂，少量用于制造电池中的合金材料、滑动轴承和焊接剂等。从废弃物当中回收锑具有重大的战略意义。 因此，制定铜冶炼烟尘中锑量测定方法，不但给冶炼厂带来良好的经济效益，对资源再生利用提供技术支撑，同时也规范了实验室检验过程，满足市场的需求。 1.1.2适用范围 规定了铜烟尘中锑含量的测定方法。适用于铜烟尘中锑含量的测定。测定范围为0.08%-7.0%。 1.1.3可行性 国内铜冶炼企业烟尘的年产量在20万吨以上，其中仅铜陵有色金属集团控股有限公司就年产2万吨。部分铜烟灰由各冶炼厂直接入炉熔炼，部分已经开始作为二次原料进入贸易市场。这样一来，实现既增加经济效益，又实现保护环境的“双赢”局面。随着环境压力和环保要求的提高，对回收利用单位资质要求越来越严，没有资质的公司纷纷将其出售，铜冶炼烟尘的贸易越来越频繁，仅广东一地的交易量一年就上万吨。 铜陵有色金属集团控股有限公司下属检测研究中心拥有CMA、CAL省级资质认定和CNAS国家实验室认可三个资质，属于面向社会服务第三方专业检测机构；主持和参与100多项国家、行业标准的起草工作，拥有丰富工作经验的技术人员和科研团队，具有较强的检测分析操作经验和深入的标准研究能力，拥有制定该方法必需的环境、设备；标准研制人员已参加过国家和行业标准制定的培训，熟料掌握标准制定规则，有利于资料整理、归纳及标准编制。 1.1.4要解决的主要问题 经查，国内外均没有铜冶炼烟灰中锑量测定的国家或行业标准。国内测定锑量的国家标