Accelerating the decarbonization of carbonaceous gold ore by suspension oxidation roasting towards the improvement of gold leaching efficiency

Eliminating the gold preg-robbing effect of carbonaceous matter in carbonaceous gold ores is crucial for gold leaching. In this study, suspension oxidation roasting was proposed to accelerate the decarbonization of carbonaceous gold ore. The characteristics of oxidation reaction process and gas release were analyzed by TG-DTA-FTIR. The phase transformation and microstructure evolution of samples during roasting were analyzed by XRD, SEM and BET. The results show that the gold preg-robbing effect was eliminated after the gasification of carbonaceous matter, and the CaO generated by decomposition of carbonates can effectively capture the SO₂. After roasting for 75 min at 650 °C in a 20% O₂ atmosphere, the total carbon removal rate reached 99.42%, the distribution of exposed gold increased from 28.85% to 77.10% and the gold leaching efficiency increased from 4.55% to 84.83%. In addition, about 70% sulfur was mainly fixed in the roasted products in the form of sulfate. Therefore, the suspension oxidation roasting process is an efficient and clean pretreatment method for carbonaceous gold ores.     

离子型稀土矿山淋洗及尾水富集试验研究

对浸矿后离子型稀土原地浸矿场采用清水进行淋洗，在184天的清水淋洗过程中，尾水氨氮值从最开始的507mg/L，降低至140mg/L，淋洗尾水pH4.52~3.10。淋洗尾水采用两级反渗透膜分离，既回收有价资源稀土，又能使出水氨氮达标。结果表明，产水氨氮浓度稳定低于15mg/L，对稀土的截留率高于98.25%，浓水中稀土离子平均浓度313.4mg/L，可进一步回收稀土资源。     

Migration and distribution of saline ions in bauxite residue during water leaching

Bauxite residue, a highly saline solid waste produced from digestion of bauxite for alumina production, is hazardous to the environment and restricts vegetation establishment in bauxite residue disposal areas. A novel water leaching process proposed here was used to investigate the dynamic migration and vertical distribution of saline ions in bauxite residue. The results show that water leaching significantly reduced the salinity of bauxite residue, leaching both saline cations Na⁺, K⁺, Ca²⁺ and anions CO^2?₃, SO^2?₄, HCO^?₃. Na⁺ and K⁺ migrated from 40–50 to 20–30 cm of the column, presenting a high migration capacity. The migration capacity of Ca²⁺ was lower and accumulated at 30–40 cm of the column. CO^2?₃ initially distributed at 20–30 cm of the column, subsequently transported to 30–40 cm of the column, and finally returned to 20–30 cm of the column along with evaporation. SO^2?₄ was originally distributed at 40–50 cm, but finally migrated to 20–30 cm of the column. Nevertheless, HCO^?₃ remained at the bottom of the column, and its migratory was less affected by evaporation.     

铋精矿加压氧化氨浸高效分离铜、硫和铋

针对湖南柿竹园铋精矿火法冶炼过程中存在的成本高、低浓度SO₂和散烟排放污染环境、有价金属综合回收率低等问题, 以柿竹园铋精矿为原料, 提出了加压氧化氨浸分离铋与铜、硫的新工艺, 研究了氨水加入量、浸出温度、浸出时间、浸出压力及浸出液固比等因素对铜、硫、铋浸出率的影响。在氨水用量1.8 mL/g_铋精矿、液固比4∶1、釜压2.8 MPa、浸出温度160 ℃、浸出时间5 h、搅拌速度600 r/min的优化工艺条件下, 铜、硫浸出率分别达93.57%和92.87%, 铋不浸出并以氧化铋形态全部入渣, 实现了铜、硫与铋的高效分离。     

福建某低品位金矿新型浸金剂浸金试验

福建某斑岩型金矿品位低、规模大,金主要以自然金形式存在,可见金的粒度较粗,为高效利用该低品位金矿,开展新型浸金剂金蝉全泥浸出试验和柱浸试验,结果表明：全泥浸出在磨矿细度为-0.074 mm占80%、矿浆浓度25%、加石灰调pH 值11.0左右、初始金蝉浓度为500 mg/L和过程中控制金蝉浓度不小于300 mg/L条件下浸出20 h,金的浸出率为93.43%,金蝉耗量为1.02 kg/t；柱浸在矿石粒度为-30 mm条件下喷淋浸出23天,金累计浸出率和金蝉累计耗量分别为86.54%和1.22 kg/t。     

湿法炼锌酸浸渣常规干燥实验研究

本文以湿法炼锌酸性浸出渣为研究对象,实验研究干燥温度、物料量、干燥时间对酸浸渣相对脱水率的影响,综合考虑干燥工艺的时效性、经济效益以及工艺效率,控制物料量为50g、干燥温度为90℃、干燥时间为80min时,酸浸渣相对脱水率可达到98.32%。实验研究对促进酸浸渣中有价金属的资源综合利用、改善环境等具有重要的指导意义。     

云南镇源难处理金精矿工艺矿物学研究

利用X射线衍射、X射线荧光光谱（XRF）、X射线能谱分析（EDX）和矿物解离分析（MLA）等检测手段对云南镇源难处理金精矿的化学组成、矿物组成、硫化物特征以及金的分布情况进行了详细的工艺矿物学研究。结果显示：该金矿以硫化矿、碳酸盐和硅酸盐类矿物为主，含有3.18%的有机碳和2.37%的无机碳。通过金的诊断浸出发现96.16%的金被硫化物包裹，少量金以单体形式存在。通过对主要载金矿物黄铁矿、辉锑矿和毒砂的粒度、包裹及裸露情况进行分析，得出大部分硫化矿以解离单体的形式存在，少部分与其他矿物共生。根据MLA测试及金的诊断浸出，认为大部分金被硫化矿完全包裹，处理该矿石时应先进行硫化物包裹层的氧化处理，再进行金矿的浸出。     

多级深度还原法制备Ti6Al4V合金粉体的基础研究

目前Ti6Al4V合金粉体的生产方法主要有雾化法、机械合金法和氢化脱氢法,它们都以Kroll法生产海绵钛为基础。使用钛的氧化物作为原料的熔盐电解法和金属热还原法仍处于研究阶段。本文依据变价金属Ti和V的氧化物在还原过程中逐级还原的特性,提出使用金属氧化物(TiO₂, V₂O₅)作为原料的多级深度还原法制备Ti6Al4V合金粉体的新思路。首先计算了TiO₂-V₂O₅-Mg-Ca体系的吉布斯自由能变,结果表明先进行镁热自蔓延反应,后进行钙热深度还原反应制备Ti6Al4V合金粉体在热力学上具备可行性。然后通过实验进行了的验证。镁热自蔓延反应产物酸浸后除去MgO可得到氧含量为15.84%的多孔Ti-Al-V-O前驱体。配入金属Ca后进行深度脱氧可得到低氧Ti6Al4V合金粉体(Al: 6.2wt.%, V: 3.64wt.%, O: 0.24wt.%, Mg: 0.01wt.%, Ca: < 0.01wt.%)。     

机械活化对粉煤灰提铝影响研究

为提高粉煤灰中铝提取率, 采用机械活化对粉煤灰进行预处理, 探讨了机械活化对粉煤灰焙烧-酸浸效果的影响。结果表明: 机械活化能提高粉煤灰比表面积、增加反应活性点, 促进活化反应的进行; 通过机械活化, 在Na₂CO₃与Al₂O₃物质的量比1.6、850 ℃下焙烧50 min后酸浸, 铝浸出率达到91.58%。     

分光光度法和光度滴定法联合测定湿法炼锌流程中钴渣浸出液中锌钴镍

湿法炼锌流程中钴渣浸出液中含有高浓度的Fe²⁺和Mn²⁺,用分光光度法测定Co²⁺和Ni²⁺时,Fe²⁺-EDTA会严重干扰Co²⁺和Ni²⁺的测定;在用光度滴定法测定Zn²⁺和Co²⁺合量时,Ni²⁺对二甲酚橙指示剂具有封闭作用,Mn²⁺亦与EDTA螯合,导致滴定结果偏高。为消除Fe²⁺和Mn²⁺对Zn²⁺、Co²⁺和Ni²⁺测定的干扰,实验进行氧化分离Fe²⁺和Mn²⁺预处理,在NaAc/Hac缓冲体系下,以EDTA作显色剂用分光光度法测定Co²⁺、Ni²⁺。在波长466nm处,Co²⁺的线性范围为50~500mg/L时与吸光度呈线性,相关系数R²为0.9992;在384nm处,Ni²⁺的线性范围为50~500mg/L时与吸光度呈线性,相关系数R²为0.9998。根据分光光度法测出Ni²⁺物质的量,加入1.1倍的丁二酮肟以除去Ni²⁺,用二甲酚橙为指示剂,EDTA鳌合-光度滴定法测定Zn²⁺、Co²⁺合量,扣减Co²⁺含量得出Zn²⁺含量。选取4个锌湿法炼锌流程中钴渣浸出液实际样品,按照实验方法中的分光光度法测定Co²⁺和Ni²⁺,光度滴定法测定Zn²⁺、Co²⁺合量,Zn²⁺、Co²⁺和Ni²⁺测定结果的相对标准偏差(RSD,n=6)均不大于0.70%,加标回收率分别为99.59%~100.41%、99.69%~100.64%、99.92%~100.08%。