黄金洞焙砂浸金率低的原因分析

采用ＴＧ－ＤＴＡ热分析法、Ｘ射线衍射法对黄金洞焙砂的结构进行了研究，结果表明，黄金洞焙砂中仍含有８％的硫，并以单质硫，Ｆｅ１－ｘＳ，Ｆｅ１－ｘ－ｙＳ和ＦｅＳ２等形式存在。由于硫化物包裹的金不能暴露于氰化液中，以及这些物质的存在会大量消耗氰化过程中所需要的氧，因而导致黄金洞焙砂浸金率低。而此焙砂分别经３００℃，５８０℃焙烧处理后，焙砂氰化浸金率相应地提高到９１．７％和９３％。因此黄金洞焙砂浸金率低的原因是脱硫阶段氧化气氛不足，脱硫不完全，是焙砂欠烧而非过烧造成的。

某高砷高硫金精矿焙砂浸金特性的研究

某高砷高硫金精矿焙砂含Au84.27 g/t,含As0.55%、S1.03%,生产现场金的氰化浸出率不足80%,迫切需要查明该焙砂的浸金特性。结合化学成分和物相分析,发现含铁物相包裹是浸金渣中残留金难以浸出的根本原因。浸金渣残留金(19.54 g/t)中包裹金占96.66%,主要包裹物相有氧化铁、毒砂和黄铁矿等含铁物相,92.68%的包裹金存在于这些含铁物相中。浸金试验中焙砂及浸金渣所达到的浸出率分别只有84.47%、16.70%,进一步验证了含铁物相中的包裹金极难浸出,焙砂的浸金率很难继续提高。

含砷锑金精矿焙砂预处理与提金工艺研究

云南某低品位难处理金矿含有砷、硫、碳、锑等多种对氰化浸金有害的杂质成分,金矿中金以包裹金为主.两段焙烧后焙砂直接氰化浸出的浸金率较低.本研究针对含砷锑硫金精矿焙砂,对比了酸浸预处理、碱浸预处理、碱性硫化物预处理等方式,结果显示,碱性硫化物预处理效果最好,金浸出率可以达到95.06%.

金精矿焙砂氯化挥发多元素综合提取新技术研究

为解决传统剧毒氰化浸出提金工艺对环境的危害,本文对金精矿焙砂直接氯化挥发提金进行了探索试验研究,试验考察了CaCl_2添加量、焙烧时间、球团粒径等主要因素对金挥发率影响情况。结果表明金精矿焙砂直接氯化提取技术可行,在条件CaCl_2加入量11%、氯化焙烧时间2h、球团粒径10mm下,Au与Ag的挥发率达98%和80%以上,实现了焙砂中金、银的高效综合回收。

高稳定性碱性硫脲体系对不同类型金矿的适应性

为考察碱性硫脲体系对不同类型金矿浸出的适应性,选用理化性质不同的6种含金物料,分析了其化学组成及矿物物相,并对其浸出行为进行了研究.结果表明,稳定剂Na2SO3和Na2SiO3大大降低了碱性硫脲的分解率,随稳定剂浓度的增大,硫脲分解率逐渐降低;而且Na2SiO3对碱性硫脲的稳定效果明显优于Na2SO3,当Na2SiO3浓度为0.3mol/L时,硫脲的分解率由72.5%降至33.8%.铁氰化钾为适合碱性硫脲浸金的温和氧化剂.碱性硫脲体系中金矿物浸出前后物相基本无变化.所选择的金矿物中均含有大量耗碱物质,使溶液的pH值由12.5很快降至中性,但稳定剂Na2SiO3能维持体系的pH值在12左右,有利于浸出过程的进行.碱性硫脲体系中伴生金属浸出率小于0.1%,浸金具有显著的选择性.碱性硫脲体系适合浸出经预处理的物相主要为SiO2的氧化矿,浸金率高达82.68%,为碱性硫脲成功应用于黄金工业生产提供了一定的理论依据.

Differences of cyanide leaching between calcine and dust from refractory gold concentrates

Differences of cyanide leaching between the calcine and the dust from a refractory gold concentrate were investigated by comparative method. Results showed that gold leaching efficiencies of the calcine and the dust were 85.31% and 54.30%, respectively, with direct cyanidation. Contents and existing forms of arsenic and carbon were the main reasons for those differences. The maximum gold leaching efficiencies of the calcine and the dust were 87.70% and 58.60%, respectively, with cyanidation after NaOH pre-leaching. Harmful elements removal, gold loss in NaOH pre-leaching and iron oxides hindrance codetermined gold leaching efficiencies of the calcine and the dust. After H2SO4 pre-leaching, the maximum gold leaching efficiencies of the calcine and the dust achieved 94.96% and 80.40%, respectively. The effect of carbonaceous matter was the main reason for differences for leaching efficiencies of the calcine and the dust. Based on those differences, two proper gold extraction processes were put forward, and gold leaching efficiencies for the calcine and the dust achieved 94.91% and 91.90%, respectively.