液态“渣-金属”化学平衡法求取渣系组元活度的探讨

简单介绍以液态“渣-金属”化学平衡法求取渣系组元活度的方法及步骤，并以此测定了CaO—SiO2-Al2O3,CaO-SiO2-MgO和CaO－B2O3等渣系中CaO的活度结果表明．正确选择金属溶剂，正确配料──包括炼制好金属料需要的有关合金和适合渣料需要的预备渣，以及正确选择测试温度和平衡所需时间，是实验成功的关键.

融熔Cu-S,Fe-S/CaO-SiO_2-Al_2O_3体系界面脱硫反应动力学的阻抗谱分析

本工作用频率响应分析法测量了融熔 Ｃｕ－Ｓ， Ｆｅ－Ｓ／ ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３体系的交流阻抗，得到了阻抗谱用 Ｒａｎｄｌｅｓ等效电路，将所得的阻抗谱用非线性最小二乘法拟合，得到了Ｃｕ－Ｓ，Ｆｅ－Ｓ／ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３体系界面脱硫反应动力学参数：溶液电阻Ｒｅ，界面反应电荷传递电阻 Ｒｃｔ，双电层电容Ｃｄ及界面脱硫反应的速率常数ｋｆ等．

Extraction of metals from a zinc smelting slag using two-step procedure combining acid and ethylene diaminetetraacetic acid disodium

A two-step leaching method in combination of acid and ethylene diaminetetraacetic acid disodium （EDTA-Na2） was applied to extract metals such as Cd, Cu, Fe, Pb and Zn from a zinc smelting slag. The results show that the extraction rates of Cd, Cu, Fe and Zn in slag reach 88.3%, 54.1%, 69.6% and 54.7%, respectively, while the extraction rate of Pb is only 0.05% leached with 1.25 mol/L sulfuric acid under the conditions of the ratio of slag to liquid of 100 g/L, 65 ℃ and 120 r/min for 2 h. However, Pb extraction rate from 1.25 mol/L sulfuric acid leached residue reaches as high as 66.5% by using 0.1 mol/L EDTA-Na2 solution. The results indicate that two-step sequential extraction procedure combining 1.25 mol/L sulfuric acid and 0.1 mol/L EDTA-Na2 solution can extensively extract Cd, Cu, Fe, Pb and Zn from zinc smelting slag.

Physicochemical and environmental properties of arsenic sulfide sludge from copper and lead-zinc smelter

Physicochemical properties of arsenic sulfide sludge(ASS) from copper smelter(ASS-I) and lead-zinc smelter(ASS-II) were examined by XRD, Raman spectroscopy, SEM-EDS, TG-DTA, XPS and chemical phase analysis method. The toxicity characteristic leaching procedure(TCLP), Chinese standard leaching tests(CSLT), three-stage sequential extraction procedure(BCR) and batch leaching experiments(BLE) were used to investigate the environmental stability. The ASSs from different smelters had obviously different physicochemical and environmental properties. The phase composition and micrograph analysis indicate that ASS-I mainly consists of super refined flocculent particles including amorphous arsenic sulfide adhered with amorphous sulfur and that ASS-II mainly consists of amorphous arsenic sulfide. The valence state of arsenic in both sludges is trivalent, but the valence composition of sulfur is quite different. The ASSs have thermal instability properties. The results of TCLP and CSLT indicate that the concentrations of As and Pd in the leaching solution exceed the standard limits. More than 5% and 90% of arsenic are in the form of acid soluble and oxidizable fractions, respectively, which explains the high arsenic leaching toxicity and environmental activity of ASS. This research provides comprehensive information for the disposal of ASS from copper and lead-zinc smelter.

Effect of additives on growth of ferronickel grains and metal-slag separation behavior

Na_(2)S,Na_(2)CO_(3),FeO,FeS and carbon were used to regulate the properties of slag or metal fractions,and their effects on metal growth and metal–slag separation behavior were investigated.The growth of ferronickel grains can be enhanced by adding these additives,and Na_(2)S was the most effective.Na_(2)S,Na_(2)CO_(3) and FeO mainly affected the properties of slag,while carbon and FeS affected the metal fraction.The onset temperature of metal–slag separation was 1297℃ for the sample without additive,which was decreased to 1123 and 1101℃ after adding 3.30 wt.%Na_(2)S and 4.47 wt.%Na_(2)CO_(3),respectively.The onset temperature of metal–slag separation was mainly controlled by the slag fraction.The average apparent activation energy of metal grain growth was 125.32 kJ/mol without additive,and it decreased obviously after adding different additives.Na_(2)S also had the most remarkable effect on the decrease in activation energy.

Chemical fractionation method for characterization of biomass-based bottom and fly ash fractions from large-sized power plant of an integrated pulp and paper mill complex

The aim of this study was to extract the biomass-based bottom and fly ash fractions by a three-stage fractionation method for water-soluble （H2O）, ammonium-acetate （CH3COONH4） and hydrochloric acid （HCl） fractions in order to access the leaching behaviour of these residues. Except for Mo, S, Na and elements whose concentrations were lower than the detection limits, the extractable element concentrations in both ash fractions followed the order H2O＆lt;CH3COONH4＆lt;HCl. The elements concentrations in this study were also lower than those in our previous studies, in which certain extraction stages followed the BCR extraction procedure.

Selective reduction process of zinc ferrite and its application in treatment of zinc leaching residues

The traditional zinc hydro-metallurgy generates a large amount of zinc ferrite residue rich in valuable metals. The separation of iron is crucial for resource recycling of valuable metals in zinc ferrite residue. A novel selective reduction roasting？leaching process was proposed to separate zinc and iron from zinc leaching residue which contains zinc ferrite. The thermodynamic analysis was employed to determine the predominant range of Fe3O4 and ZnO during reduction roasting process of zinc ferrite. Based on the result of thermodynamic calculation, we found thatV（CO）/V（CO＋CO2） ratio is a key factor determining the phase composition in the reduction roasting product of zinc ferrite. In the range ofV（CO）/V（CO＋CO2） ratio between 2.68% and 36.18%, zinc ferrite is preferentially decomposed into Fe3O4 and ZnO. Based on thermogravimetric （TG） analysis, the optimal conditions for reduction roasting of zinc ferrite are determined as follows： temperature 700？750 °C, volume fraction of CO 6% and V（CO）/V（CO＋CO2） ratio 30%. Based on the above results, zinc leaching residue rich in zinc ferrite was roasted and the roasted product was leached by acid solution. It is found that zinc extraction rate in zinc leaching residue reaches up to 70% and iron extraction rate is only 18.4%. The result indicates that zinc and iron can be effectively separated from zinc leaching residue.

Adsorption of copper ions on porous ceramsite prepared by diatomite and tungsten residue

In order to realize resource utilization of industrial tungsten residue and treatment of heavy metal wastewater in mining and metallurgical area of south China,a novel ceramsite was prepared with the main raw materials of diatomite and tungsten residue.The adsorption behavior of copper ions in solution on the ceramsite was investigated.Results indicated that the surface of the newly-developed ceramsite was rough and porous.There were lots of pores across the ceramsite from inner to outside.MnFe2O4 was one of the main components of the ceramsite.The Cu^2＋adsorption capacity by the ceramsite reached 9.421 mg/g with copper removal efficiency of 94.21%at 303 K,initial Cu^2＋concentration of 100 mg/L and dosage of 0.5 g after 300 min adsorption.With increase of ceramsite dosage,the total adsorption amount of Cu^2＋increased,but the adsorption capacity decreased.The adsorption capacity increased with the increase of solution p H.The isothermal adsorption of Cu^2＋by the ceramsite fitted the Freundlich model better.The adsorption mainly occurred on a heterogeneous surface,and was a favorable process.The adsorption process closely followed the pseudo-second kinetic equation.In initial stage of wastewater treatment,the adsorption process should be controlled mainly by diffusion,and the removal of Cu^2＋can be improved by enhancing agitation.

Enhanced recovery of zinc and lead by slag composition optimization in rotary kiln

High-efficiency recovery of Zn and Pb from silicon-rich zinc leaching residues is realized in a rotary kiln.Characterizations by means of XRD,SEM,EDS and ICP reveal that the leaching residue contains 12.4 wt.%SiO_(2),16.1 wt.%Zn,and 7.4 wt.%Pb.Thermodynamic analysis shows that metallic vapor of Zn and Pb can be easily generated from the zinc leaching residue at 1150-1250°C inside the rotary kiln.Viscosities and melting points of 13 slag compositions were analyzed and three slag compositions(47wt.%SiO_(2)-23wt.%CaO-30wt.%FeO,40wt.%SiO_(2)-28wt.%CaO-32wt.%FeO,and 40wt.%SiO_(2)-30wt.%CaO-30wt.%FeO)possessed the desirable physical properties,with the melting point and viscosity in the range of 1150-1280°C and 0.2-0.5 Pa·s,respectively.The industrial tests show that adopting the optimized slag composition can contribute to very high recovery rates of Zn and Pb(97.3%for Zn and 94.5%for Pb),corresponding to slags with very low average contents of Zn and Pb(0.51 wt.%Zn and 0.45 wt.%Pb).The National-Standard leaching tests of the water-quenched slags result in 1.82 mg/L Zn,~0.01 mg/L Cu,0.0004 mg/L As,~0.01 mg/L Cd,0.08 mg/L Pb,and~0.02 mg/L Hg in the leachate,verifying the detoxification of the zinc leaching residue at the same time.

Optimization of brine leaching of metals from hydrometallurgical residue

An orthogonal array,L16(45),was used to examine the effects of four parameters,including NaCl concentration,H2SO4 concentration,temperature and pulp density,on the recovery of Cu,In,Pb and Zn from a hydrometallurgical residue via brine leaching.The results show that temperature of leaching solution has a significant effect on the recovery of Cu,In and Zn,while H2SO4 concentration has an obvious influence on these metals extraction.Both pulp density and NaCl concentration significantly affect Pb extraction.Based on the orthogonal array experiments,the optimum conditions for the extraction of Cu,In,Pb and Zn from hydrometallurgical residue are NaCl concentration of 250 g/L,H2SO4 concentration of 1.00 mol/L,temperature of 85℃,and pulp density of 100 g/L.After 1 h of treatment at these optimum conditions,over 91% of the metals are extracted from the residue.Brine leaching is therefore suitable for the recovery of metals from hydrometallurgical residues.

Extraction of metals from automotive shredder residue: Preliminary results of different leaching systems

The study is focused on the extraction of valuable metals from automotive shredder residue(ASR)by different leaching solutions.First,ASR samples were roasted at 600°C to simulate a thermal treatment processing.Distilled water,citric and sulphuric acid were preliminarily investigated,thus two further full factorial systems entailing H2SO4–H2O2and H2SO4–H2O2–Fe3+were tested.The preliminary experimental results showed that0.1 mol·L-1H2SO4solution extracted 100%of Cu,Fe and Zn,whereas citric acid leached 100%of Zn and Pb,59%of Fe and 62%of Cu;whereas,H2SO4–H2O2and H2SO4–H2O2–Fe3+(Fenton's)leaching media showed that Cu,Fe and Zn can be extracted simultaneously and completely from the ASR ashes before final disposal.

Recovery of valuable metals from zinc leaching residue by sulfate roasting and water leaching

Zinc leaching residue(ZLR),produced from traditional zinc hydrometallurgy process,is not only a hazardous waste but also a potential valuable solid.The combination of sulfate roasting and water leaching was employed to recover the valuable metals from ZLR.The ZLR was initially roasted with ferric sulfate at640°C for1h with ferric sulfate/zinc ferrite mole ratio of1.2.In this process,the valuable metals were efficiently transformed into water soluble sulfate,while iron remains as ferric oxide.Thereafter,water leaching was conducted to extract the valuable metals sulfate for recovery.The recovery rates of zinc,manganese,copper,cadmium and iron were92.4%,93.3%,99.3%,91.4%and1.1%,respectively.A leaching toxicity test for ZLR was performed after water leaching.The results indicated that the final residue was effectively detoxified and all of the heavy metal leaching concentrations were under the allowable limit.

Extraction of nickel from molybdenum leaching residue of metalliferous black shale by segregation roasting and acid leaching

The recovery of nickel from molybdenum leach residue by the process of segregation roasting-sulfuric acid leaching-solvent extraction was investigated. The residue was characterized by microscopic investigations, using X-ray fluorescence spectrometry （XRF） and X-ray diffractometry （XRD） techniques and the residue after segregation roasting was characterized by chemical phase analysis method. A series of experiments were conducted to examine the mass ratio of activated carbon （AC） to the residue, segregation roasting time and temperature, sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, addition amount of 30% H2O2, stirring speed （a constant） on the leaching efficiency of nickel. A maximum nickel leaching efficiency of 90.5% is achieved with the mass ratio of AC to the residue of 1：2.5, segregation roasting time of 2 h, segregation roasting temperature of 850 ℃, sulfuric acid concentration of 4.5 mol/L, liquid-to-solid ratio of 6：1, leaching time of 5 h, leaching temperature of 80 ℃, addition of 30% H202 of 0.6 mL for 1 g dry residue. Under these optimized conditions, the average leaching efficiency of nickel is 89.3%. The nickel extraction efficiency in the examined conditions is about 99.6%, and the nickel stripping efficiency in the examined conditions is about 99.2%.

Study on the Effect of Catalyst Properties on Residue Hydroconversion

The effect of catalyst properties on residue oil hydroconversion was studied at moderate operating conditions(at a temperature of 400 ℃, an initial hydrogen pressure of 10 MPa, and a reaction time of 4 h) in a batch mode slurry phase with different catalyst samples. The results showed that the catalyst acidity had a good effect on residue conversion and MCR(micro carbon residue) conversion but brought about higher coke yield. Residue conversion was thermally induced but the catalyst acidity changed its conversion route. A catalyst with higher metal loading, higher hydrogenation activity and appropriate pore size had higher sulfur and metal removal rate, higher MCR conversion and also a lower coke formation. The activity of spent commercial catalyst AS1 and DS1 was slightly lower than the corresponding fresh ones but was still high enough for residue oil hydroconversion. It assumes that the role of the catalyst is to activate hydrogen species toward reaction with an aromatic carbon radical to yield a cyclohexadienyl type intermediate which will turn into liquid and also to absorb the mesophase which can easily aggregate to form coke.

内蒙古获各琦铜矿构造控矿分析

内蒙古获各琦铜矿位于狼山-渣尔泰山Cu-Pb-Zn多金属成矿带,处于华北板块北缘西段,地层出露前寒武纪变质岩,岩浆岩活动时间长,强度大,构造复杂,成矿地质条件十分优越。通过矿区地表和井下系统研究表明获各琦铜矿主要发育在渣尔泰山岩群阿古鲁沟组第二岩段,本矿田总体为一向西倾伏的复式倒转向斜。

Physicochemical and environmental characteristics of alkali leaching residue of wolframite and process for valuable metals recovery

Physicochemical and mineralogical characteristics of an alkali leaching residue of wolframite were studied by XRD,SEM−EDS,chemical phase analysis,mineral liberation analyzer(MLA),and TG−DSC methods.Batch leaching tests,toxicity characteristic leaching procedure(TCLP)tests and Chinese standard leaching tests(CSLT)were conducted to determine the environmental mobility of toxic elements.The results show that,due to the high contents of W,Fe,Mn,Sn,and Nb,the residue is with high resource value,but the content of a toxic element,As,is also high.The existing minerals of the investigated elements mainly occur as monomer particles,but it is difficult to extract these valuable metals by conventional acid leaching due to their mineral properties.The release of As increases over time in acidic environment.The leaching concentration of all investigated harmful elements through TCLP is within the limiting value,while the leaching concentration of As through CSLT exceeds the limiting value by more than 4 times,so the residue is classified as hazardous solid waste based on the Chinese standard.A process for valuable metals recovery from this residue was proposed.Preliminary experimental results indicated that the main valuable metals could be extracted effectively.

Codes From Strongly Regular (α,β)-reguli

Strongly regular (α,β)-reguli are a class of incidence structures with given conditions which were introduced by Hamilton and Mathon. We introduce two classes of codes constructed from strongly regular (α,β)-reguli within PG(k-1,q). The codes are related with two-weight codes intimately.