Arsenopyrite Oxidation with Ozone: Stoichiometry and Kinetics

When the recovery of precious metals by standard cyanidation is less than 80%, the ore is classified as refractory and needs an oxidizing pretreatment before cyanidation. Arsenopyrite is one of the main sulfide matrixes where occurs refractory gold. In this work, the arsenopyrite leaching in acid media was studied using ozone as an oxidizing agent. The results obtained show that arsenopyrite leaching is carried out in a stoichiometric way: one mole of Fe and one mole of S are leached by each mole of As leached. A maximum of 60% arsenopyrite leaching was obtained when 1 g (?25 µm) was submitted to acid leaching in 800 mL of 0.18 M acid solution (either chlorhydric, nitric, or sulfuric acid), mechanically stirred at 800 rpm and with the addition of 1.2 L/min oxygen gas containing 0.079 g O₃/L at 25° for 60 min. Although the apparent activation energy estimated was 4.07 kJ/mol, it is suggested that the system is controlled by chemical reaction.     

石灰湿法加压氧化预处理含砷金矿的研究

本文研究了加压氧化法预处理含砷金矿，由于加入木质素磺酸钠作表面活性剂，从而成功地用石灰乳液作为碱性物料预氧化含砷难冶金矿，获得金的氰化浸出率在85％以上     

高海拔地区难处理金精矿的细菌氧化预处理及氰化浸金

针对高海拔地区某难处理金精矿含砷高的特点,采用细菌氧化预处理工艺,考察在一定工艺条件下,Fe, S, As脱除率及金的氰化浸出率,并对金精矿及氧化渣、氰化渣进行了分析. 结果表明,Fe, S, As脱除率均达85%以上,金氰化浸出率为88.09%,说明对该类矿物采用细菌氧化预处理工艺具有可行性. 机理分析表明,细菌氧化金精矿是通过直接与间接协同作用机理;氧化酸液中和主要是将液相中砷以化学性质稳定的砷酸铁沉淀除去,将重金属离子等以氢氧化物沉淀去除.     

在气升式反应器中用中度嗜热混合菌浸出含砷难浸金精矿

在分批浸出基础上,以15％矿浆浓度在气升式反应器中用中度嗜热混合菌采用半连续方式补加无铁9K溶液浸出含砷难浸金精矿,降低体系中铁和砷离子浓度,提高含砷难浸金精矿铁砷脱除率。结果表明,在补加流量为每次333mL时,金的氰化回收率达到90％以上,比直接氰化提高了2倍。     

微生物脱砷预处理难冶含砷金矿提金的研究

用化能自养的氧化铁硫杆菌和氧化硫硫杆菌，对河北半壁山含砷金精矿进行了公斤级的预处理氧化脱砷实验．在细菌预处理反应器中的连续和批式脱砷实验表明，目前选育的菌种是有效的．严格控制工艺条件，可以在4天左右便脱砷率高于80％．后续氰化提金实验证实，金的总回收率可达90％以上．用微生物脱砷预处理难冶含砷金矿有金浸出率高、便于固定浸出的砷、免除对环境污染的优点，是有很好应用前景的处理难冶含砷金矿的技术路线．     

自含砷合碳难处理金矿中提取金的研究─Ⅰ.氨水脱砷-石灰加压氧化-氰化

针对甘肃省坪定金矿含金、砷高、金部分地赋存于脉石、脉石为碱性、属于难选难冶矿的特点，提出了氨水脱砷－石灰加压氧化－氰化新工艺．当原矿含金8．7g／t及13．0％砷时，砷可脱除95％，金可浸出85％．技术及经济指标预计均较满意．     

Ozonation Pretreatment of Gold-Silver Pyritic Minerals

The use of ozone for the oxidation of cyanidation wastewater has been studied since the 1950's. In the last 2 decades, the use of ozone to oxidize sulfide ores has been studied. This report presents some of the results obtained concerning the use of ozone in the oxidation of raw ores containing gold and silver as well as the treatment of tails or residues of the cyanidation process. The results show that oxidation treatment with ozone prior to cyanidation may help to optimize this process, mainly through reduction of the consumption of cyanide.     

Pre-Concentration of Ultrafine Crushed Hematite Ores

In this study, a lean hematite ore was crushed to produce ultrafine particles using a high pressure grinding roll and then pre-concentrated using a high gradient magnetic separator with a steel rod matrix to reduce the ore tonnage for milling and grinding energy consumption. Pilot test results showed that the primary concentrate grade was increased by 6.98 percentage points from the crude ore with 18.34% Fe at an optimum pre-concentration condition obtained using a matrix with a rod diameter and a rod gap that both measure 4 mm. The concentrate recovery reached a maximum of 86.13% with a tailings yield of 37.61%. Primary concentrates were separated further, and clean concentrates with a grade of 67.15% were obtained.

In a magnetic field around a matrix rod, the magnetic capturing force on coarse hematite particles was increased, but such force on fine hematite particles was decreased as the matrix rod diameter increased at the same background magnetic field intensity. Considering gravity and viscous resistance of locked particles, the matrix with large diameter rods (e.g., 4 mm) could effectively and completely recover these particles. By contrast, the matrix with small diameter rods (e.g., 1 mm) could efficiently recover fine particles but not coarse particles such as lean-locked particles.     

氰化尾渣无害化处理工艺的优化改进

介绍了山东恒邦冶炼股份有限公司氰化尾渣无害化处理的生产工艺,针对传统因科法处理氰化尾渣有价金属不能有效回收的问题进行优化改进,利用高含硫烟气对氰化尾渣进行无害化处理,使氰化尾渣处理达标,由危废转化成一般固废,并实现有价元素金、银、铜的综合回收,降低处理成本。     

氨性催化氧化-氰化法处理含砷难浸金矿的研究(Ⅱ)

本文概述了氨性氧化-氰化法处理含砷难浸金矿的扩大实验结果．对于含有砷、锑、汞、碳的丹寨金精矿，其金品位为17．6g／t，金的氰化率可达84％与小型实验结果相符．     

硫铁矿烧渣综合利用试验研究

为避免硫铁矿烧渣对环境的污染 ,以硫铁矿烧渣为原料 ,通过添加活性还原剂 ,用废硫酸直接还原浸出铁并制铁黄 ,同时用以二 - 2乙基己基磷酸为主体的三元萃取剂萃取回收浸液中的铜 ,用全泥氰化和锌粉置换工艺从浸渣中提取金银 ,较经济有效地回收利用了烧渣中的有价金属 ,铁、铜和金的回收率分别达到了 93.31%、80 .78%和 90 .18%。     

超临界水氧化法选冶难选金矿石的初步实验

介绍了超临界水氧化法(SCWO)选冶难选金矿石的初步实验,采用SCWO技术,在反应温度550oC、操作压力25 MPa及反应时间10 min时,使难选金矿石回收率从≤35%提高到92.8%.在超临界氧化反应过程中,有机物被氧化为CO2和水,S氧化为硫酸盐,沉积于渣中;虽然As被氧化生成As2O3,但由于几乎不溶于超临界流体,最终固定在渣中. 氧化反应后排放的超临界水清洁,符合国家《污水综合排放标准》,并且不排放有害气体,整个选冶过程符合清洁生产工艺要求.     

焙烧酸浸渣中铜的形态对铜、金浸出率的影响

以某黄金冶炼厂含铜金精矿为研究对象,采用铜化学物相分析及浸出方法研究了焙烧?酸浸?氰化工艺处理含铜金精矿过程中焙烧酸浸渣中铜形态对铜、金浸出率的影响. 结果表明,含铜金精矿焙烧酸浸及氰化浸出时,铜形态对铜、金浸出率有显著影响,当酸浸渣中氰化易溶铜(氧化铜、次生硫化铜)含量大于0.10%时,金浸出率降低. 以原生硫化铜矿为主的含铜金精矿,适当提高焙烧温度、延长焙烧时间、增加初始酸浸酸度可有效降低酸浸渣中氰化易溶铜含量,提高铜浸出率,减弱其对金浸出率的影响.     

借鉴硫酸法钛白生产工艺提高黄金回收率的设想

为了提高难浸金矿中黄金的回收率,提出了借鉴硫酸法钛白生产工艺,利用70％左右浓度硫酸浸出焙烧矿中的铁,使铁进入酸浸液中,剥离铁中的包裹金,从而提高难浸金矿中黄金产率,对黄金行业具有一定的开拓和创新意义,具有良好的经济效益和社会效益。     

自含砷含碳难处理金矿中提金研究──Ⅱ.硫氨脱砷-铜氨催化氧化-氰化

针对甘肃坪定金矿含金、砷高，脉石碱度高，砷矿物中雌黄、雄黄高的特点，研究了硫氨脱砷－铜氨催化氧化－氰化新工艺，采用了三种新技术，即稀氨水溶解雌黄、雄黄湿法转化为雌黄以及在氨水中氧化时用铜离子作催化剂.本研究为小型实验，结果为其后进行的3kg级扩试所证实。     

Pretreatment with Ozone for Gold and Silver Recovery from Refractory Ores

In this work ozonization was studied as pretreatment for two Mexican refractory ores in order to increase the gold and silver extraction. Two methods for contacting ozone with the mineral were studied (indirect and direct). The indirect method did not change the precious metals recoveries for mineral sample A, but increased those of mineral B (from 53 to 88% for gold and from 26 to 78% for silver). The direct pretreatment, only tested in mineral A, did not affect gold and silver recoveries but decreased the extraction time from 40 to 24 hours for maximum metal recovery.     

搅拌槽反应器中中度嗜热浸矿菌预处理含砷金矿

从多个矿坑、煤堆废水中富集中度嗜热浸矿菌,并在搅拌反应器中经过两年的长期驯化,获得能耐受高矿浆浓度和具有抗砷性的浸矿混合菌. 对浸矿混合菌进行耐高矿浆浓度的驯化,保持矿浆浓度为200 g/L,改变两种金矿的配比,提高驯化体系中砷含量,进行耐砷性驯化. 用驯化的浸矿混合菌对难处理金矿进行生物氧化预处理,矿浆浓度为200 g/L,砷含量为8 g/L,14 d时菌体浓度最大,达2′109 mL-1,22 d时砷浸出率为59.93%. 采用限制性酶切片段长度多态性分析对浸矿14和22 d时的微生物多样性进行分析,发现存在Sulfobacillus sp., Acidithiobacillus caldus, Ferroplasma thermophilum和Pseudomonas sp..     

天冬氨酸对氧化亚铁硫杆菌胞外多聚物的影响

以天冬氨酸为营养辅助因子,研究其对氧化亚铁硫杆菌生长及胞外多聚物成分的影响。结果表明,与对照组相比,最大菌体量提高17%,生长周期缩短了15 h;培养至23 h时,Fe2+氧化速率比对照高66.67%,环境pH提前15 h达到最低点,并降低8.72%。培养25 h后,胞外多聚物中蛋白质含量增加21.95%,多糖含量增加9.19%。添加天冬氨酸可有效促进氧化亚铁硫杆菌的生长,缩短生长周期;其可能的机理为其促进了氧化亚铁硫杆菌胞外多聚物中蛋白组分的表达。     

三相流化床动力学特征的影响因素

利用电导探头测试技术,以不同粒径的玻璃珠颗粒、金精矿、金矿氰化尾渣为固相,空气为气相,不同粘度的液体为液相,对三相流化床中不同测孔的电导率进行测试和计算,系统研究了颗粒粒径(dp)、密度(r)、质量(q)、表观气速(Ug)、液体粘度(ml)等对相含率的影响. 结果表明,dp从0.05 mm增加到0.15 mm,气含率(eg)增加2%~3%,而固含率(es)减小2%~4%;其他条件相同,密度大的颗粒es和eg较小;随q增加,eg降低,es增加,玻璃珠颗粒每增加100 g,eg减小约2.5%,es增加约1.5%;随Ug增大或减小,eg和es亦随之增大或减小;随ml增大或减小,eg和es亦呈增大或减小趋势.     

氰化尾渣中有价元素回收现状与展望

氰化尾渣是我国的大宗危险固体废物。这种固体废物含有可回收的有价元素,如铜、铅、锌、金、银、硫、铁等。对氰化尾渣的综合利用既可以回收这些有价元素,实现矿石资源的最大化利用,又可以减少氰化尾渣中残存的药剂对环境的危害。本文从氰化尾渣的性质出发,总结了氰化尾渣的预处理方法,介绍了回收铜铅锌、硫铁、金银的研究现状,并指出现阶段存在的主要问题。针对研究现状和存在的问题,提出新工艺的开发、新药剂的研制、尾矿的再利用等发展方向。氰化尾渣的顺利解决将为社会带来一定经济效益和环境效益。