摘要
针对高硫高砷难处理金精矿在常规提金工艺中金浸出率低、环境污染大的问题,本研究聚焦分段搅拌生物预氧化技术,选育出具备高效脱硫脱砷性能的预氧化菌种。具体为,将初始混合菌种(以嗜铁、嗜酸菌等为主)两次分段搅拌驯化后,通过金精矿单次加矿,在矿浆浓度15%条件下生物氧化7 d,最终砷、硫氧化率分别达到83.67%、48.73%以上,金的提取率从45.58%提高到了84.30%。与此同时,随着砷氧化率的提高,预氧化渣中金的提取率也逐渐升高,得出高砷高硫难处理金精矿中砷的氧化率与金的提取率呈正相关的结论。本研究证实了分段搅拌生物预氧化工艺是一种高效、环保且经济的预处理方法,为高硫高砷金精矿的生物预氧化-环保提金工艺提供技术支撑。
To address the issues of low gold leaching efficiency and significant environmental pollution associated with conventional gold extraction processes for high-sulfur and high-arsenic refractory gold concentrates,this research develops a segmented agitation bio-preoxidation technique to selectively cultivate highly efficient preoxidative bacterial strains capable of removing sulfur and arsenic.The gold concentrate sample used in the experiment has a particle size of 80%passing 400 mesh(0.038 mm).Its primary chemical composition includes FeS_(2),FeAsS,and SiO_(2).The main elemental contents of the ore sample are as follows:Fe 27.46%,As 8.94%,S 27.69%,and Au 21.64 g/t.Using the bacterial strain GRINM-FS,the experiment was conducted under the following conditions:grinding fineness of 80%passing 400 mesh(0.038 mm),culture medium 4.5K,pulp density of 15%(850 mL of bacterial suspension and 150 g of ore),with a single ore addition of 150 g.The process was carried out at a temperature of 40℃,initial pH of 1.6,and a pre-oxidation period of 7 d.The final parameters recorded are pH=1.1,ORP=523 mV,residue rate 98.08%,and an arsenic oxidation rate of only 19.51%.The bio-preoxidized residue contains 24.11 g/t of gold.After 24 h of whole-ore cyanidation carbon-in-pulp testing,the gold leaching rate is 45.12%.The initial mixed bacterial culture,primarily consisting of iron-oxidizing and acidophilic bacteria such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans,undergoes two stages of adaptive training through segmented agitation.First adaptive training stage:initial strain GRINM-FS,grinding fineness of 80%passing 400 mesh(0.038 mm),culture medium 4.5K,pulp density of 15%,ore addition method six incremental additions(each time adding 25 g of gold concentrate when the system ORP rebounds to 560 mV above),temperature of 40℃,initial pH of 1.6,pre-oxidation time of 7 d,final parameters pH of 0.66,ORP of 529 mV,residue rate of 78.28%,and arsenic oxidation rate of 63.09%.The bio-preoxidized residue contains 28.31 g/t of gold.After 24 hours of cyanidation carbon-in-pulp testing,the leached residue contains 7.14 g/t of gold,resulting in a leaching rate of 74.86%.Second adaptive training stage:strain GRINM-SF1,grinding fineness of 80%passing 400 mesh(0.038 mm),culture medium 4.5K,pulp density of 15%,ore addition method initial addition of 25 g,followed by 125 g after the potential rebounded to 560 mV,temperature of 40℃,initial pH of 1.6,pre-oxidation time of 7 d,final parameters pH of 0.54,ORP of 562 mV,residue rate of 67.00%,and arsenic oxidation rate of 83.42%.The bio-preoxidized residue contains 32.32 g/t of gold.After 24 h of cyanidation carbon-in-pulp testing,the leached residue contains 5.08 g/t of gold,achieving a leaching rate of 84.44%.After these two adaptive training stages,under the same conditions of single ore addition and 15%pulp density with 7 d of bio-oxidation,the arsenic and sulfur oxidation rates are 83.67%and 48.73%,respectively.The gold extraction rate increases remarkably from 45.58%to 84.30%.The main components of the bio-preoxidized residue remain FeS_(2),FeAsS,and SiO_(2).Additionally,phases such as FeAsO4 and KFe(SO_(4))2 are detected,which are secondary precipitates formed after the bio-oxidative dissolution of the ore sample.Comparative experiments on bacterial adaptation clearly demonstrate that gradual,segmented ore addition significantly enhances the bacterial strains'oxidative activity toward the gold concentrate.Specifically,after two adaptive trainings,the arsenic and sulfur oxidation rates in the single-addition bio-preoxidation system increase to 83.67%and 48.73%,respectively.Compared to the non-adapted single-addition bio-preoxidation,these rates are improved by 64.16%and 43.85%,respectively.Moreover,the gold extraction rate rises from 45.58%to 84.30%.These results indicate that adaptive training through segmented ore addition markedly improves the oxidation rates of arsenic and sulfur in the gold concentrate within just seven days,leading to a substantial increase in gold extraction from the bio-preoxidized residue.Furthermore,the comparison shows that as the arsenic oxidation rate increases,so does the gold extraction rate,suggesting a positive correlation between the two in this specific gold concentrate.This study confirms that the segmented agitation bio-preoxidation process is an efficient,environmentally friendly,and cost-effective pretreatment method.It provides crucial technical support for the application of bio-preoxidation combined with eco-friendly gold extraction technologies for high-sulfur and high-arsenic gold concentrates.
作者
田炳阳
赵娟
聂榕
尚鹤
刘学
温建康
TIAN Bingyang;ZHAO Juan;NIE Rong;SHANG He;LIU Xue;WEN Jiankang(National Engineering Research Center for Environment-friendly Metallurgy in Producing Premium Non-ferrous Metals,China GRINM Group Co.,Ltd.,Beijing 101407,China;Beijing Engineering Research Center of Strategic Nonferrous Metals Green Manufacturing Technology,Beijing 101407,China;GRINM Resources and Environment Tech.Co.,Ltd.,Beijing 101407,China;General Research Institute for Nonferrous Metals,Beijing 100088,China;School of Metallurgy,Northeastern University,Shenyang 110819,China)
出处
《有色金属(冶炼部分)》
北大核心
2026年第1期70-77,共8页
Nonferrous Metals(Extractive Metallurgy)
基金
国家重点研发计划项目(2022YFC2105304)。
关键词
金精矿
生物预氧化
脱硫
脱砷
环保提金
gold concentrate
bio-oxidation
desulfurization
de-arsenification
eco-friendly gold extraction
