陕西某黄金冶炼厂焙烧氰化浸渣提金方法研究

陕西某黄金冶炼厂的焙烧氰化尾渣中可供选矿回收的组分只有金和银,其中金品位为4.92 g/t左右,银品位为21.77%。工艺矿物学研究结果表明,原料中的金主要为裸露半裸露金和硅酸盐中金,铁主要赋存在赤褐铁矿中。根据原料性质特点,进行了详细的条件试验研究。试验结果表明:该焙烧氰化尾渣经高温焙烧—氰化浸出的提金工艺流程,可得到金和银的浸出率分别为66.26%和90.26%,为该地区焙烧氰化尾渣资源的开发提供了技术支撑。     

从焙烧氰化尾渣中回收金、银

对于含铜、砷金精矿,国内外黄金冶炼厂通常采用焙烧氰化法提取金、银,但所产的氰渣中金、银的含量较高,其品位分别为Au1.5～2.5g/t、Ag150～250g/t.如何从焙烧氰化尾渣中回收Au、Ag,合理地利用矿产资源,提高企业的经济效益,是目前黄金选冶工艺中急待解决的难题.为此,我们以山东招远黄金冶炼厂焙烧氰化尾渣为原料进行了试验研究.结果表明,采用添加剂进行尾渣焙烧-氰化浸出的工艺,金、银的回收率分别达到61.54%和76.81%.该方法投资少、成本低、简单易行,具有较好的经济效益和社会效益,值得推广应用.     

氯化挥发法回收氰化尾渣中的金银

山东某黄金冶炼公司氧化焙烧氰化尾渣中金含量为5.85g/t、银含量为22.92g/t、SiO2含量为26.23%。为回收利用该尾渣中的金银,对其进行了氯化挥发焙烧试验。结果表明:尾渣中SiO2含量和入炉球团含水率越高越不利于金银的氯化挥发;在CaCl2加入量为8%、入炉球团含水率为0.95%、氯化焙烧温度为1000℃、焙烧时间为40min时,获得了金、银的氯化挥发率分别为93.21%和61.61%的指标。采用氯化挥发法可以实现氰化尾渣中金银的有效回收。     

边磨边浸全泥氰化工艺在北衙金矿的运用

北衙金矿4000 t/d选厂是一座常规全泥氰化炭浆厂。投产后,各项工艺指标基本达到了设计水平,但尾渣金、银品位偏高,金浸出率不到90%,银浸出率不到30%。为了进一步降低尾渣品位,提高金、银浸出率,选厂进行了一系列的工艺技改及试验研究。经过研究得出,采用"边磨边浸"工艺流程可以有效地提高金、银的浸出率。于是选厂进行技改,运用了"边磨边浸"工艺流程。技改后,工艺指标得到了明显的提高,年平均金浸出率提高了2.97%,达到92.40%,银浸出率提高了9.07%,达到35.49%;尾渣金品位下降了0.10 g/t,降至0.16 g/t,尾渣银品位下降了3.43 g/t,每年可为选厂增加5000万元以上的经济效益。     

某银精矿氰化尾渣中铅和锌的浮选回收试验

某浮选银精矿经常温常压碱式氧化预处理-氰化浸出金、银后的氰化尾渣中,含有铅、锌、金、银等有价元素,金属矿物主要为黄铁矿、方铅矿、闪锌矿和毒砂,并含有少量含银矿物。该尾渣粒度很细,含泥量大,铅、锌矿物被氧化,使铅、锌的选别回收受到影响。对该尾渣进行铅、锌的浮选试验,结果表明,铅矿物不能得到有效富集而形成铅精矿,但可以获得锌品位为55.62％,锌回收率为66.15％的合格锌精矿,锌精矿中金、银品位为66.94 g/t和538.9 g/t,金、银回收率为47.96%和25.67%。     

磨矿介质对氰化尾渣浸出提金效果的影响研究

为对比陶瓷介质和铸铁介质搅拌磨矿对氰化尾渣中金浸出效果的影响,以中国黄金集团三和金业有限公司的金矿氰化尾渣为研究对象,开展了浸出提金试验。研究结果表明,在磨矿细度-6 μm 占 90%、JC 浸出剂用量 40 kg / t 及浸出时间 12 h 的条件下,采用陶瓷介质磨矿可获得浸出渣 Au 1. 29 g / t、浸出率 54. 45%的技术指标,采用铸铁介质磨矿可获得浸出渣 Au 2. 15 g / t、浸出率 39. 45%的技术指标。与传统铸铁介质磨矿相比,陶瓷介质磨矿条件下金的浸出率显著提高。 在陶瓷介质磨矿过程中加入 Fe³⁺后,金的浸出效果明显下降,表明 Fe³⁺的加入不利于金的浸出。 机理分析表明,铸铁介质磨矿过程中会产生Fe³⁺,Fe³⁺会在矿物表面形成羟基氧化铁( FeOOH),阻碍了 CN^-的扩散过程,恶化浸出环境,从而降低了金的浸出率。     

含铜金精矿铅盐预处理浸金技术研究

为了降低氰化钠用量,对某含铜4.92%的金精矿开展了铅盐抑铜预处理研究。结果表明,在氰化浸出前加入醋酸铅可以抑制铜的浸出、增强金银浸出、降低氰化钠消耗。醋酸铅预处理金精矿-氰化浸出的优化条件为: 浸出前直接添加醋酸铅150 g/t,磨矿细度-0.037 mm粒级占95%,浸出时间48 h,氰化钠浓度0.5%,pH=12,矿浆浓度40%。在此条件下浸出渣中金品位降至1.20 g/t,金浸出率达97.55%,银回收率60.28%,氰化钠耗量14.37 kg/t。该工艺具有良好的经济效益。     

氰化尾渣氯化焙烧工艺研究

针对新疆某冶炼厂氰化尾渣,采用"制球—干燥—氯化焙烧"工艺进行处理提取金、银,并考察了氯化焙烧条件对金属挥发率的影响。研究结果表明,在氯化钙添加量为7%、焙烧温度为1100℃条件下反应60 min,金、银的挥发率分别达到98%和62%,铜、铅、锌的挥发率达到80%以上。焙烧后球团中金和银的含量分别降至0.47 g/t和6.12 g/t。     

某含金、银黄铁矿综合利用试验

为高效综合利用某含金、银黄铁矿精矿,在对其矿石性质研究的基础上,试验研究采用提纯—焙烧预处理—烧渣氰化浸出贵金属的工艺。浮选预处理抛尾得到了含金1.22 g/t、银50.41 g/t、硫50.26%,金、银、硫回收率分别为97.82%、96.53%、95.47%的高品位黄铁矿精矿。高品位黄铁矿精矿经焙烧预处理,烟气用于制酸,烧渣通过氰化浸出回收金、银,获得了金、银浸出率分别为71.99%、64.35%的较好指标。氰化浸渣含硫0.22%、铁品位为65.82%、二氧化硅含量为3.24%,符合铁精矿质量标准,实现了金、银、硫、铁等有价金属元素的综合回收,对矿业资源的综合利用和可持续发展具有重要的现实意义。     

某高泥质银金矿氰化浸出及柱浸对比试验

针对某银金矿石含泥质高、堆浸时渗滤性差等问题,分别进行了全泥氰化浸出和柱浸浸出对比研究。试验结果表明:采用制粒—固化—柱浸工艺流程,可获得金浸出率为81.98%、浸渣金品位为0.17 g/t,银浸出率为53.98%、浸渣银品位为8.26 g/t,氰化钠耗量为0.444 kg/t、石灰耗量为6 kg/t的较好指标,研究结果为下一步工业化生产提供了技术保障。     

Enhanced leachability of gold and silver in cyanide media: Effect of alkaline pre-treatment of jarosite minerals

Composite samples of tailings containing gold (1.35 g/t) and significant amounts of silver (155 g/t) were subjected to batchwise cyanide leaching to assess the feasibility of extracting gold and silver. The tailings are waste solids arising from flotation and leaching operations whereby the flotation product (sphalerite concentrate) is calcined and then solubilised into dilute sulphuric acid solution and eventually sequestered from the electrolyte by electrowinning. Silver and gold are part of the zinc refinery residue, flotation tailings and to a limited extent the calcine leach tailings. Mineralogical results showed that composite tailings are refractory in nature (44% quartz, 17% silico aluminates and 12% jarosites).The concept of enhancing gold and silver recovery from the tailings focused on firstly decomposing the jarosite minerals by alkaline pre-treatment and then secondly leaching with cyanide solution. These two steps ensured that free gold and silver found in the zinc refinery residue and in the jarosite minerals could be leached simultaneously. The composite tailings were treated with Ca(OH)₂ solutions and then heated to 90 °C for 2 h to decompose the silver-bearing mineral (Ag,PbFe₃(SO₄)₂(OH)₆). The alkaline pre-treated tailings were then subjected to cyanide leach tests at different NaCN dosages (2.5–10 kg/t) and particle size (96–200 μm). Without an alkaline pre-treatment stage, leach efficiencies achieved were 41% and 25% for gold and silver, respectively at 40 °C and 8 h mixing time. But, better leach efficiencies (55% for Au, 81% for Ag) were achieved after the feed was pre-treated with Ca(OH)₂. The leaching mechanism of gold was explained by the shrinking sphere model denoted by surface chemical reaction.     

福建某金精矿焙砂浸出金、银试验研究

福建某金精矿焙砂主要组成矿物为赤铁矿与石英,金、银含量分别为31.27 g/t、824 g/t。采用自主合成的嗜金1号药剂从稀硫酸脱铜后的该金精矿焙砂中提取金、银。结果表明,在嗜金1号用量为5 g/L、pH为11、液固比为5 mL/g、浸出温度为25 ℃、浸出时间为24 h时,金与银的浸出率分别达到92.76%、85.02%。比以氰化钠为浸出剂时,金浸出率提高了3.73个百分点。嗜金1号的浸金效果较优,且嗜金1号较氰化钠对环境的影响较弱。因此,嗜金1号可以用于含金焙砂的金浸出工艺。     

Improvement of cyanidation practice at Goldcorp Red Lake Mine

Goldcorp Red Lake Mine processes a mildly refractory high grade gold ore with 77.8 g/t Au and 1.9% arsenopyrite, 1.7% pyrite and 0.2% pyrrhotite at a grind of 77% −37 microns. A cyanidation study was conducted to determine the necessary retention time of the leach circuit and the optimal gold extraction and cyanide consumption. Results have shown that the gold leaching kinetics could be significantly improved by the addition 100–200 g/t lead nitrate directly in the grinding circuit, followed by a 6 h cyanidation. A 1 month trial indicated a throughput of 810 tpd can be sustained without detrimental effect on gold extraction. However, the mill is currently limited by the underground operation to a throughput ranging from 650 to 700 tpd for a 55 h retention time. In the event of future throughput increase over 810 tpd value, lead nitrate could become an essential part of the leaching efficiency. The experimental work indicated a gold extraction at 87.1–87.4% (tailings ∼9.8 g/t Au) which is similar to plant performance. The associated cyanide consumption was 0.7 kg/t. Gold dissolution can efficiently be conducted at an average cyanide concentration of 400 ppm. Previous control of cyanide concentration in the plant was 700 ppm in the first leach tank to 350 ppm NaCN at the end. Testwork realised in the mill allowed a 32% cyanide reduction predicted by the on-site cyanidation study. The new cyanide concentration is ranging between 500 ppm in the first leach tank and 300 ppm NaCN at the end of the leaching circuit. The cyanide consumption of the plant was reduced from 1.0 to 0.68 kg/t with reduction of effluent treatment costs. Grinding finer (91% −37 microns) slightly increased the gold extraction (tailings lower by 0.4 g/t) but lowers the leaching kinetics, increases cyanide consumption (35%) and the arsenic dissolution.     

双氧浸出处理含碲金银精矿的试验研究

对含碲金银精矿的性质、氰化浸出技术现状以及生产实践情况进行了介绍与总结,对此类精矿进一步提高金、银浸出率进行了试验探索并取得技术突破。试验结果表明,对含碲金银精矿进行氰化浸出,金的氰化浸出率可达到98%以上,氰渣金品位降低到1 g/t以下,银回收率稳定在95%以上,效果较为明显。提出的"双氧浸出"工艺为研究改进氰化工艺提供了一条新思路。     

西藏某石英脉型金矿选矿试验研究

西藏某石英脉金矿主要载金矿物为银金矿,嵌布粒度较细且不均匀,金品位3.22g/t,为主要回收元素,银品位19.50g/t,为可综合回收元素。针对矿石性质,采用浮选-浮选尾矿氰化浸出联合工艺流程对矿石中的金进行回收。经一粗一精二扫、中矿顺序返回的闭路浮选流程,可获得浮选金精矿含金95.81g/t、金回收率84.34%的指标;浮选尾矿进行氰化浸出,金作业浸出率为79.31%,对原矿回收率为12.42%。联合工艺最终获得金总回收率96.76%的指标。其中浮选金精矿中银品位为407.01g/t、金尾矿中银品位为5.97g/t、精矿银回收率为68.78%,氰化浸出作业中银作业浸出率为51.53%,对原矿浸出率为15.98%,银综合回收率为84.76%。     

含铜氧化金矿氨氰选择性提金试验研究及工业应用

针对含铜氧化金矿采用氨氰选择性浸出提金,考察了分段加药制度、硫酸铵用量、矿石粒度等对金浸出率及浸出液铜金比的影响。结果表明:当硫酸铵用量8.00 kg/t,氰化钠用量0.60 kg/t,石灰用量5.00 kg/t,矿浆浓度40.00%,磨矿细度-0.074 mm粒级含量不低于95.00%时,平均金、铜浸出率分别为86.66%和1.16%。工业试验连续运行70 d,氰化尾渣金品位约0.55 g/t,金吸附率99%,金解吸率99.2%,电积回收率99.5%,金精炼回收率99.5%,金锭纯度99.99%,产品金达到国标Au-1标准。     

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Au 84.27 g/t, 含As 0.55%、S 1.03%, 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。     

川西某金矿选矿试验探索

对川西某金矿的矿石特征进行了研究,在此基础上进行了全泥氰化试验和单一浮选试验。全泥氰化浸渣金品位为0.46 g/t,浸出率为87.5%,另外矿石中金属硫化物较多,且金的粒度细小,有碍于氰化的砷矿物含量较高,不利于金矿物的提取。相对而言,单一浮选工艺流程更适合该金矿床,原矿金品位为3.86 g/t,经过一次粗选、两次精选、两次扫选,获得的精矿金品位为65 g/t,金回收率91.7%。