铁矾法炼锌工艺中回收银的研究

在铁矾法炼锌工艺中,溶解于溶液中的Ag~+吸附于锌焙烧料中残余的闪锌矿ZnS(0.3—0.5wt%S)表面,或生成银铁矾型化合物使银富集于酸浸渣。控制沉矾过程中焙砂的用量,保证沉矾前液清亮是降低铁矾渣中的银含量的有效措施。高酸浸出渣中的银铁矾型化合物须酸分解转化为可浮的银矿物。故从高酸浸出渣Ag(300g/t)中可用超酸浸出—硫化浮选法回收银,银的回收率76.54%,银精矿品位4456.0g/t。     

碱性焙烧再次沉矾法回收黄铁矾渣中的铟

从湿法炼锌的富铟铁钒渣中回收海绵铟.将黄铁矾渣碱性焙烧、稀酸浸出、再次沉矾、二次铁矾渣经焙烧、酸浸、还原可得海绵铟.主要考察了铁钒渣650℃焙烧时的碱渣配比、焙烧时间,焙烧渣浸出温度和再次沉矾时间等因素的影响.结果 表明,碳酸钠和黄铁矾渣的质量比为0.36,焙烧90 min后,用1 mol/L稀硫酸在85℃C下浸取150 min,浸出液在90℃下经14h再次沉矾,铟含量可提高23倍.二次矾渣600℃C焙烧后用1.0 mol/L稀盐酸浸出,浸出液直接用铝板置换,可得到93％以上的海绵铟,铟的直收率85％.     

从锌冶炼渣中回收银的试验研究

某锌冶炼渣含高品位银360 g/t, 银在浸出渣中的形态比较复杂, 且绝大部分银被黄钾铁矾包裹, 回收困难。根据浸出渣性质进行了试验研究, 最终采用焙烧浸出除铁、焙烧浸出渣浮选富集银, 得到的银精矿品位为3 899 g/t, 银回收率为88.09%, 实现了资源的综合回收。     

热酸浸出-铁矾法炼锌工艺中富集锗的研究

进行了"热酸浸出-铁矾法炼锌工艺中锗和银的富集和回收"的实验室扩大试验,在10个循环试验中,工艺流程畅通,以黄钾铁矾沉铁代替通常的钠或铵铁矾沉铁使锗在矾渣中的损失减少到5.0%以下,锗和银均富集于高酸浸出渣中,其品位分别为0.0325%和0.162%.     

热酸浸出—铁矾法炼锌工艺中富集锗的研究

进行了“热酸浸出—铁矾法炼锌工艺中锗和银的富集和回收”的实验室扩大试验 ,在 10个循环试验中 ,工艺流程畅通 ,以黄钾铁矾沉铁代替通常的钠或铵铁矾沉铁使锗在矾渣中的损失减少到 5 0 %以下 ,锗和银均富集于高酸浸出渣中 ,其品位分别为 0 0 32 5 %和 0 16 2 %.     

铁矾渣还原焙烧自硫化研究

为解决铁矾渣大量堆存带来的资源浪费和重金属污染,及传统焙烧回收处理工艺会产生SO_2等二次污染的问题,同时实现铁矾渣中主要有价金属的回收利用,提出了铁矾渣还原焙烧固硫的预处理方法。以铁矾渣热分解过程和热力学计算为基础,通过考察焙烧条件对铁矾渣中主要有价金属锌的硫化率、硫的固定率及物相转变的影响,对铁矾渣还原焙烧自硫化过程进行了研究。结果表明:在焙烧温度为900℃,碳粉添加量为18%,碳酸钠添加量为5%,焙烧时间为90min的条件下,锌的硫化率和硫固化率分别可达93.47%和87.69%。焙烧产物主要以硫化物形式存在,可通过浮选等方式富集。铁矾渣还原焙烧可以实现Zn等主要有价金属的综合回收预处理并避免焙烧过程中SO_2的排放。该研究对其它重金属硫酸盐的清洁处理具有重要的指导意义。     

黄钾铁矾渣回收银的试验研究

某黄钾铁矾渣含银221 g/t左右,锌5.94％,铅8.48％,硫10.79％,铁28.81%。银在渣中的形态比较复杂。经还原焙烧,硫化钠活化处理后,用HD1配合HD2进行浮选。试验表明：通过两次粗选三次精选三次扫选流程,试验取得了相当好的指标,最终得到了银品位达到 7515.62 g/t、回收率81.49％左右的银精矿。     

焙烧对含菱磷铝锶矾高磷铁矿石酸浸除磷的影响

以河南某地含菱磷铝锶矾高磷铁矿石为对象,研究了焙烧对含菱磷铝锶矾高磷铁矿石酸浸法除磷的影响及机理。结果表明：焙烧对含菱磷铝锶矾铁矿石的酸浸除磷至关重要。难溶于酸的菱磷铝锶矾在加热到500~700 ℃时会逐渐分解成易溶于酸的六方AlPO₄,使酸浸除磷效果大大提高;但焙烧温度在1 025 ℃以上时,由于AlPO₄从六方型转变成较难溶于酸的立方型,导致除磷效果下降。对于试验矿样,最佳的焙烧温度为800 ℃,保温时间为1 h。     

铁矾渣直接还原-浮选回收银工艺研究

采用直接还原-浮选新工艺流程回收铁矾渣中的银。结果表明,银矿物被包裹在铅铁矾矿物中难以充分解离,直接浮选效果不理想;通过直接还原反应可以破坏铅铁矾矿物的化学结构从而使包裹银暴露易于硫化,同时降低锌含量,避免Zn²⁺对浮选的不利影响。直接还原-洗矿-浮选闭路流程得到银品位2 125 g/t、回收率80.35%的银精矿,浮选效果良好。     

红土镍矿制备黄钠铁矾的研究

为确定红土镍矿酸化焙烧溶出液中硫酸镍溶液除铁的工艺条件,以低品位红土镍矿硫酸铵焙烧熟料溶出液为研究对象,Na2CO3为造矾试剂制备了黄钠铁矾。造矾最佳试验条件为:反应温度95℃、反应时间4 h、终点p H值为2.5,除铁率在99.5%以上,并采用XRD、SEM和化学分析手段对黄钠铁矾进行了物化表征,显示在此条件下所得到的黄钠铁矾具有分散性良好、外形规则的,包含多个光滑颗粒的花球状的结构。     

低污染钠、铵铁矾法除铁

本文在钠铁矾、铵铁矾沉淀除铁动力学研究的基础上,研究了含钠、铵等沉矾离子及三价铁离子的锌焙砂高酸浸出液的预中和、以及中和后溶液的钠铁矾、铵铁矾沉淀除铁,探讨了湿法炼锌低污染钠、铵铁矾法除铁的途径及有效性。     

Fundamental study of silver deportment during the pressure oxidation of sulphide ores and concentrates

Effort to recover silver during the pressure oxidation requires an understanding of the behaviour of silver. In this work, pressure oxidation of silver sulphide was investigated in the temperature range of 110–150 °C and in the sulphate media. The subsequent deportment of silver was monitored to shed light on the path of aqueous silver.Silver sulphide reacts during the pressure oxidation and silver is released into the solution. Under the deoxygenated condition, aqueous silver can precipitate as silver sulphide. However, the presence of oxygen minimises this reaction and any silver sulphide precipitated is oxidised back to aqueous silver. Therefore, the major collector of aqueous silver is jarosite specie and its precipitation kinetics increases with increasing temperature and lead sulphate concentration. However, initial acidity has a negative effect on the rate of precipitation of silver and ferric ions. Silver precipitation is fast and finished before the ferric precipitation leading to the zoning of the silver in the core of the jarosite specie. During cyanidation, only the silver ion in the outer crystal planes of the jarosite is accessible to the cyanide resulting into low extraction of silver. Soluble iodide can be added to the pressure oxidation to precipitate silver iodide, which is soluble in cyanide. However, in the presence of ferric and iodide, some aqueous silver is sequenced preferentially into the jarosite and this is pronounced at high temperature because of the enhanced stability and the precipitation kinetics of jarosite.     

含银氧化锰矿高温氯化过程研究

对高温下Mn-Cl-O系及Ag/ASCl平衡图进行分析,找出了理论上银、锰的存在形态。以内蒙呼盟含银氧化锰矿石为原料,在实验室对高温氯化过程中影响银挥发率的因素进行了研究。得出了氯化剂用量,氯化温度、球团直径及氯化时间与银挥发率的定量关系。95％～98％的锰残留在球团中,主要以Mn_2O_3和MnSiO_3形态存在。在最佳条件下银挥发率为98.8％,球团残银12.1g/t。     

Zinc and silver recoveries from zinc–lead–iron complex sulphides by pressure oxidation

Acid pressure oxidation followed by cyanide leaching of the residue is a promising process for the treatment of complex sulphides and the recovery of precious metals along with the base metals will improve the economy of the process. However, silver is incorporated into the jarosite specie during the pressure oxidation and cyanide leaching of the residue yields very low silver extraction.In this work, iodide was added to the pressure oxidation of zinc–lead–iron complex sulphides to prevent the deportment of silver ions into the jarosite phase. At low temperature range (110–130 °C), the silver ions were completely sequenced into the silver iodide phase because of the fast precipitation kinetics of silver iodide and its stability at low temperatures. The leaching of the residue in cyanide solution yielded high silver extraction (above 90%).Silver extraction from the residue decreased when the pressure oxidation was conducted at high temperatures (140–150 °C). At this temperature range, the enhanced stability and the precipitation kinetics of the jarosite specie posed a challenge by competing (with iodide) for silver ions. This competition was minimised by using moderately high initial acid for the pressure oxidation.High zinc extraction was achieved during the pressure oxidation. Also, there were appreciable iron precipitation and acid neutralisation of the slurry. The resulting pregnant solution is suitable for zinc recovery by electrowinning and the residue can be leached for silver and gold extraction.     

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。     

某高砷银铜精矿的利用研究

根据某高砷银铜精矿的物质组成 ,分析了对该精矿利用的技术方案 ,简述了对这一精矿进行的低温焙烧、化学除砷、氨浸萃取提铜和氨浸渣浸银等试验研究以及取得的技术指标