低毒环保浸出提金技术研究与应用

根据四儿沟金矿矿石性质和金物相,进行了低毒环保药剂替代氰化钠浸出提金实验室对比实验、现场对比优化试验,发现低毒环保药剂"金蝉"、"喜金"相比氰化钠浸出提金具有环保无毒、溶金能力强、稳定性好、使用单耗低、药剂成本低等优点。通过对原有氰化钠浸出提金工艺的优化改进,技改后工艺指标稳定,浸出回收率高,经济社会效益突出,开创了金矿企业降低环保压力的新途径,推广应用前景良好。

湿法协同氧化氰化浸出提金工艺新型助剂

一种湿法协同氧化氰化浸出提金工艺新型助剂，由辅助剂SPW－01和核心助剂SPW－02两部分组成，其中SPW－01由胺盐和氟化物组成，用工业品直接复配即可制得。SPW－02由氧化剂，PH调节剂，络合剂三部分构成，氧化剂自制后与工业品复配即可制得。本发明的二种助剂配套使用，可拓宽氰化提金工艺的可直接利用资源，提高金的回收率，缩短氰化浸出时间，降低氰化物用量，且适用性广，操作简便，制造工艺简单易行，经济效益显著，特别适用于难处理金矿采用。

某金矿山硫精矿再磨再浸提金工艺活性炭吸附性能研究

某金矿山采用了浮选回收金、银、铜-硫精矿再磨再浸炭浆法提回收金工艺,随着生产时间的延长,吸附率出现了逐步下降的问题,导致硫精矿氰化浸出工艺中金的回收率大幅降低,本文针通过试验并结合生产实践,对活性炭吸附性能进行探究。

降低含砷金精矿两段焙烧提金过程中氰化物用量的途径

针对某含砷难处理金精矿两段焙烧工业生产中焙砂氰化物单耗较高,达到8～10kg/t(焙砂)的实际情况,本文研究探索了焙砂氰化浸出工艺,通过调整生产工艺,氰化钠的单耗降低至4.0kg/t(焙砂),不但生产成本降低了,而且金的浸出率也相应提高到90%以上,为企业创造了良好的经济效益。本文对含砷难处理金精矿两段焙烧生产过程中降低氰化物消耗、降低渣金品位以及指导金精矿两段焙烧实际生产具有指导作用。

Bioleaching of heavy metals from contaminated alkaline sediment by auto- and heterotrophic bacteria in stirred tank reactor

Bioleaching Xiangjiang River alkaline sediment contaminated by multiple heavy metals was investigated. Multiple metals in alkaline sediment possess significant toxicity to aquatic organisms or humans and will greatly inhibit bioleaching. The bioleaching method using autotrophic bacteria mixed with heterotrophic bacteria can solve this problem successfully. The experiment results showed that bioleaching efficiencies of Zn, Mn, Cu, and Cd were 95.2 %, 94.2 %, 90.1 %, and 84.4 %, respectively. Moreover, the changes of heavy metal concentrations in different fractions in contaminated sediment before and after bioleaching were analyzed by selective sequential extraction, and it was discovered that the main fractions of Zn, Mn, Cu and Cd after bioleaching are Fe-Mn oxide, organic associated form and a residual form. Its biotoxicity decreased greatly. The bioleaching heavy metals from sediment using autotrophic bacteria combined with heterotrophic bacteria can effectively improve the bioleaching efficiency and reduce toxicity.

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%.

Extraction of valuable metals from low-grade nickeliferous laterite ore by reduction roasting-ammonia leaching method

Nickel and cobalt were extracted from low-grade nickeliferous laterite ore using a reduction roasting-ammonia leaching method.The reduction roasting-ammonia leaching experimental tests were chiefly introduced,by which fine coal was used as a reductant.The results show that the optimum process conditions are confirmed as follows:in reduction roasting process,the mass fraction of reductant in the ore is 10%,roasting time is 120 min,roasting temperature is 1 023-1 073 K;in ammonia leaching process,the liquid-to-solid ratio is 4:1(mL/g),leaching temperature is 313 K,leaching time is 120 min,and concentration ratio of NH3 to CO2 is 90 g/L:60 g/L.Under the optimum conditions,leaching efficiencies of nickel and cobalt are 86.25% and 60.84%,respectively.Therefore,nickel and cobalt can be effectively reclaimed,and the leaching agent can be also recycled at room temperature and normal pressure.

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.

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.