【作者】 谢兆凤；

【导师】 杨天足；

【作者基本信息】 中南大学 ， 有色冶金， 2011， 博士

【摘要】 研究开发了用火法湿法联合工艺综合回收脆硫铅锑矿精矿中有价金属的新工艺流程。脆硫铅锑矿精矿经熔炼(配料时加入纯碱和煤粉),硫以硫化钠的形式进入熔炼渣中,同时产出铅锑合金；铅锑合金用于直接吹炼生产锑白产品,吹炼锑白后产出的粗铅进入电解铅系统生产电铅,电铅阳极泥用来回收银等；从熔炼渣中回收的碱(硫化钠)用于浸出脆硫铅锑矿精矿中的锑,以制造焦锑酸钠产品和硫代硫酸钠副产品；熔炼渣经碱回收后,最终富集有来自原料中的锌、铁、铟等金属元素,其中的锌、铁等元素大都以硫化物的形式存在,可通过浮选方法分离出锌精矿,从而使脆硫铅锑矿精矿中的锌、铟等有价金属得以回收。对脆硫锑铅矿碱性还原熔炼过程进行理论分析,在碱性熔炼主过程中主金属铅锑及金属银等进入金属相,而伴生元素铜、铁、锌等基本上不参与熔炼反应而直接以硫化物形式进入渣相；硫则以硫化钠的形式进入渣相。对铅锑合金氧化吹炼过程进行热力学计算,铅锑合金中的铁、锡等杂质可通过氧化精炼除去；砷则通过碱性氧化方式脱除；在500～1000℃范围内,合金中的锑主要以三氧化二锑形式进入气相,而不是以金属锑的形式进入气相。确定了脆硫铅锑矿精矿碱性熔炼的具体条件为：配料比例为脆硫铅锑矿：纯碱：煤粉；石灰浆=100：50：10；10,料柱1.0-1.5m、风量61～65m3/min.风压30-60mmHg.中心温度1400℃、熔渣温度1000℃、焦率16.8%。在此条件下,床能达到110t球团/(m2·d)；金属入合金直收率Pb 85.67％.Sb 82.870％.Ag 87.08％；金属回收率Pb 94.03％. Sb 96.70％.Ag 89.33％.Zn 97.63％.In 68.33％；铜、砷的入渣率Cu72.63%、As 68.88%；熔炼渣渣率(按投入的精矿计)65.6%；熔炼渣含Na2S 52%；合金品位(Pb+Sb)97.80％；其中Pb 53.13％.Sb 44.67％;锑氧粉产出率(按投入的精矿计)7.36%；入炉物料中带入的硫有99.3%被固定在熔炼渣中,炉子烟气中S02平均浓度为588 ppm,已经达到工业废气二类排放标准,较好地消除了SO2废气污染。熔炼渣中硫化钠浸出试验的最佳条件为S：L=1：4、温度90℃、时间90min时,硫化钠的浸出率约为91%,所得滤液含硫化钠约110g/L锑浸出率平均达到91.83%,杂质元素砷也有部分被浸出,浸出率为80%,熔炼渣浸出渣(锌矿)的渣率约为50%；熔炼渣浸出渣中锌和铁等元素基本上都以硫化物形式存在于渣(锌矿)中,此锌矿经化学浮选可产出高银铟含量的多金属型锌精矿。采用压缩空气作氧化剂氧化硫代亚锑酸钠溶液,氧化时间大于45h,溶液中锑的沉淀率约98%左右,氧化后液中锑的浓度小于1g/L,产出的焦锑酸钠产品达到电子工业级二级品的质量要求。通过加硫酸中和以及加硫酸亚铁可部分除去氧化后液中的砷和锑,使其浓度分别降至0.05g/L和0.3g/L以下后,通过浓缩、结晶生产出的硫代硫酸钠产品达到二级品的质量要求。采用碱性精炼进行除去粗铅锑合金中杂质元素的实验研究,向熔体中鼓入空气时,可使得氧气能充分与金属面接触,从而达到良好的除杂效果,选择合适的碱性精炼体系为氢氧化钠+空气体系。精合金产出率平均为95.84%,杂质元素的去除率分别为(%)：Sn 88.30、As 96.45、Cu 36.10、S 56.64。主金属铅锑的直收率分别为(%)：Sb91.98、Pb97.70。精合金中砷的含量可以降至0.010%以下；吹炼锑白过程的实验条件为合金熔体温度(660±30)℃、吹风温度约100℃、合金中锑含量15%～40%,吹风风量及压力控制标准为使合金液表面产生微皱。吹炼锑白时锑的氧化率为73.34%；吹炼后的底合金(底铅)Sb、Pb的含量分别为15%和83%左右；采用提高结晶温度的方法制备大粒度锑白产品,控制实验条件为锑浓度15%～40%、合金熔体温度650～690℃、结晶(空间)温度360～470℃、吹管离金属液面的距离≥50mm,锑白产品的粒度可达到0.6μm以上。全流程Pb、Sb、Ag、Zn的总回收率分别达到92.1%、93.5%、97.6%、68.3%；74%As进入铁砷渣；Cu 72.6%进入锌矿,27%进入铅系统。与传统的烧结-鼓风炉工艺对比,所研究工艺具有流程简单、效率高、中间物料少、铅锑合金质量高、金属回收率高、各种元素走向合理、利于综合回收和环境保护等优点。更多还原

【Abstract】 Recovery of valuable metals from jamesonite concentrate with united pyrometallurgical and hydrometallurgical technology is studied. First, jamesonite concentrate is smelted (soda and coal are added into the raw material), sulfur is put into smelting slag in the form of Na2S, and then lead-antimony alloy is produced. The antimony trioxide product is produced by directly blowing lead-antimony alloy, the obtained crude lead is transferred into the lead electrolysis system to produce electrolytic lead product, and silver in the anode slime is recovered. Then, Na2S recovered from smelting slag is used for antimony leaching from jamesonite concentrate to produce sodium pyroantimonate product and sodium hyposulfite by-product. Finally, the other metals such as zinc, iron and indium in the concentrate are enriched in the smelting slag, where Na2S has been recovered. This enriched metals such as zinc and iron are mostly in the form of sulfide, and can be separated by flotation. Thus, zinc, indium and other valuable metals are recovered from the zinc concentrate.In this study, the results of smelting process analyzed in theory shows that lead, antimony, silver and so on can easily be reduced into the metal phase (lead-antimony alloy) during smelting process. However, copper, iron, zinc and other elements is too diffcullt to be reduced, so that they exist in the smelting slag in the form of sulfide. In addition, sulfur is transferred into the smelting slag in the form of sodium sulfide.Thermod-ynamics of white antimony blowing from lead-antimony alloy has been researched. Iron, tin and other impurities can be removed with oxidation refining. Arsenic is removed by adding soda. In the temperature range of 500～1000℃, the vapor pressure ratio of antimony oxide to lead oxide (psb2O3/pPbP) is higher than that of antimony to lead (psSb/pPb)-Antimony is mainly transferred into gas phase in the form of antimony trioxide during lead-antimony alloy blowing.These raw materials of alkaline smelting jamesonite concentrate are mixed according to the mass ratio of jamesonite concentrate/soda/coal/ lime slurry equal to 100:50:10:10. And then they are prepared into pellets by a honeycomb briquet machine for the intensity, dimension and permeability of these pellets are suitable for blast furnace smelting.The smelting conditions are as follows:material column height-1.0-1.5m,air amount-61-65m3/min,air pressure-30-60mmHg, central temperature-1400℃, slag temperature-1000℃, coal rate-16.8%, and bed capability-110t pellet/(m2·d). The ratio of Pb, Sb, Ag into the alloy is 85.67%, 82.87%,87.08%, respectively. The recovery of Pb, Sb, Ag, Zn, In is 94.03%,96.70%,89.33%,97.63%,68.33%, respectively. The ratio of Cu and As entering into the slag is 72.63%and 68.88%. The smelting slag yield is 65.6% containing 52% sodium sulfide. The Pb and Sb content of lead-antimony alloy is 97.87%,with Pb being 61.66% and Sb being 36.21%. Antimony oxide powder recovery(based on concentrate input) is 7.36%. The sulfur from the materials is fixed by 99.3% as the sodium sulfide in the smelting slag, and SO2 concentration in the waste gas is 588 ppm reaching the industiral waste gas emission standard.During the industrial test of sodium sulfide leaching, the optimum conditions are as follows:S:L-1:4, temperature-90℃, time-90min. The leaching; of sodium sulfide is about 91%, the concentration is about 110g/L, the leaching of antimony is 91.83%, most part of As is leached and the rate is 80%, and the leaching slag contains 50% zinc. In the zinc slag, the metal elements such as zinc and iron exist in the form of sulfide. Zinc concentrate with high silver and indium content can be obtained by flotation. The sodium sulfide solution can be used to leach antimony in jamesonite concentrate or mixed antimony and lead oxides. The antimony leaching solution can be oxidized to produce sodium pyroantimonate product by pumping air. When the oxidation time is more than 45h, the sedimentation of antimony is 98%, and the antimony content in the filtration is less than 1g/L. The grade of the sodium pyroantimonate product meets with the second electronic industrial quality requirement. Antimony and arsenic can be decreased to 0.05g/L and 0.3g/L, respectively, by adding sulphuric acid to neutralize the oxidation solution or adding ferrous sulfate to precipitate them, and then qualified sodium thiosulfate can be produced by concentration and crystallization. The experiments of impurity removal from lead-antimony alloy by refining with sodium hydroxide such as arsenic show that better effects can be obtained by pumping air into the melt to enlarge reaction area. Thus, the NaOH+air system is selected as the alkaline refining system. The yield of refined Pb-Sb alloy is 95.84%, the removal of impurities such as Sn, As, Cu, S are 88.30%,96.45%,36.10%,56.64%, respectively. The direct recoveries of lead and antimony are 97.70%and 91.98%,separately. The As content can decrease to 0.010%. The conditions of antimony trioxide blowing are as follows:The melt temperature is (660±30)℃, air blowing temperature is about 100℃, the antimony content of the alloy is in the range of 15%～40%, the air amount and pressure are controlled to ruffle the melt surface. Under the above conditions, the antimony oxidation recoveries is 73.34%,with the contents of Sb and Pb in the alloy melt 15%and 83%. And then the great granularity is produced by increasing the crystallization temperature being 360～470℃, the distance from blowing pipe to molten alloy surface is more than or equal to 50mm. As a result, the granularity of the antimony trioxide exceeds 0.6μm.In the whole flow, the comprehensive recoveries of Pb, Sb, Ag and Zn are 92.1%,93.5%,97.6%,68.3%, respectively. As enters into the iron-arsenic residue by 74%. Cu enters into the zinc slag by 72.6%and into the lead system by 27%.Compared with the traditional sintering-blast furnace process, the process has the advantages of simple flow, high efficiency, less middle materials, high lead-antimony alloy quality, high metal recovery, better comprehensive utilization of resources, and less polution. So it is an energy-saving and environment-friendly process.更多还原