【作者】 龙仲胜；

【导师】 胡岳华；

【作者基本信息】 中南大学 ， 矿物加工工程， 2007， 硕士

【摘要】 现有工业矿床有向贫、细、杂转移的趋势。因此,对浮选作业提出了更高的要求。丰山铜矿属矽卡岩型铜矿床,矿石中除富含铜外,尚伴有钼、金、银、硫等可供综合回收。金属矿物主要有黄铁矿、黄铜矿、斑铜矿、磁铁矿、辉铜矿、铜蓝、辉钼矿等;金银矿物为自然金、金银矿、自然银、碲银矿、碲金银矿等。金银矿物嵌布较为复杂,其特点:一是金银矿物在脉石矿物中呈不均匀星点状分布;二是金银矿物与黄铜矿、斑铜矿紧密共生。现场采用一粗二扫三精、粗精矿再磨单独处理铜硫分离流程。在原矿含铜0.9%、金0.2～0.4g/t、银7～10g/t的情况下,获得铜精矿含铜20.47%、金5.16g/t、银162.27g/t,铜回收率85.26%,硫精矿品位36.5%,实际金回收率54%、银回收率57%的结果。本研究试图在现有选别技术指标的基础上,将金、银的回收率进一步提高。在对原矿进行矿物组成、物相分析、金属矿物嵌布特征、粒度组成分析的基础上,分别采用混合浮选,优先浮选等方法,分别对石灰用量、调整剂用量、原矿磨矿细度、捕收剂用量以及闭路流程对浮选指标的影响进行了试验研究。研究证明:通过调整现场现有工艺流程有关参数,采用混合浮选流程,可使铜的回收率达到85%～88%,金的回收率达到75%左右,银的回收率达到72%左右。综合矿样(A)在原矿磨矿细度65%-0.074mm的条件下,可使铜的回收率达93.58%,金的回收率达82.09%,银的回收率达76.81%,硫的回收率达69.41%。对于B矿样,在磨矿细度为70%-0.074mm时,铜的回收率为92.72%～94.64%,金的回收率63.02%,银的回收率65.76%～67.34%,表明采用混合浮选流程是成功的。论文采用电化学方法,研究了黄铜矿和黄铁矿与黄药的作用机理,结果表明:双黄药的形成是导致黄铜矿和黄铁矿浮选的主要因素,但并不是唯一的疏水实体,黄铜矿和黄铁矿表面还有其它疏水物质生成。黄铁矿在石灰介质中腐蚀电化学研究表明,石灰体系对矿物的溶解有强烈的抑制作用,捕收剂的加入对黄铁矿表面的反应没有明显影响,矿物不可浮。利用密度泛函以及从头算法,对黄铁矿表面电子结构以及浮选电化学过程中的电子转移进行了计算与分子动力学模拟,研究表明,对于本征黄铁矿表面来说,电子由黄药向黄铁矿表面转移,黄药将会在其表面发生吸附。对于S空位的黄铁矿(100)来说,由于表面导带与价带交叠,矿物表面具有较高的电子和空穴浓度,在适当条件下表面可与捕收剂强烈作用。对于Fe空位的黄铁矿表面来说,由于表面费米能级较高,因此捕收剂难于在矿物表面发生电子传递。石灰与黄铁矿作用的分子动力学模拟表明,CaOH~+和OH~-两种离子在黄铁矿表面的吸附能力都强,因此石灰作为调整剂时,黄铁矿会受到抑制。更多还原

【Abstract】 Ore from the existing minerals deposits trends towards being more complicated and lower grade.Fengshan copper mine is a skarn type of copper deposit,With exception of copper rich in ore,the associated molybdenum,gold,silver and sulfur etc,can be recovered comprehensively.The dominant metallic minerals in the ore are pyrite, yellow pyrite,peacock copper,siderites,grayantimony,indigo copper and molybdenum glance etc.Gold and silver minerals are native gold, gold-silver minerals,native silver and telluric gold-silver minerals etc. The dissemination of gold-silver minerals is more complicated,which are characterized by both unevenly stellar distribution of gold-silver minerals in gangue ore and close association of gold-silver minerals with yellow pyrite and peacock copper.The circuit of rougher flotation—scavenging—recleaner flotation and rough concentrate regrinding to separately process the separation of copper and sulfur is used on site.Under conditions that grades of feed ore are 0.9%Cu,0.2-0.4g/t Au and 7-10g/t Ag,it can result in copper concentrates assayed 20.7%Cu,5.16g/tAu and 162.27g/tAg and sulfur concentrates assayed 36.5%,the copper recovery of 85.26%,gold recovery of 54%and silver recovery of 57%are obtained.Based on the existing technical index of selective separation of ore,the author makes an attempt to further increase the recovery of gold and silver.On the basis of the analysis of minerals composition,mineralogical phase,dissemination characteristics of metallic minerals and size distribution the ore,bulk flotation and selective flotation etc,are used respectively.The effect of dose of lime,conditioning agent and collector, and grinding fineness on flotation index was investigated.It has been shown that adjusting the related parameters of processing circuit the recovery of copper,gold and silver can be up to 85%-88%,about75%and 72%or so respectively.The recovery of copper,gold,silver and sulfur of composite ore samples（A）can be up to 93.58%,82.09%,76.81%and 69.41%respectively,for composite ore samples（B）,the recovery of copper,gold and silver is 92.72%～94.64%,63.02%and 65.76%～67.34% respectively under condition of ground fineness of 70%（-0.074mm）.Based on electrochemical measurement,the interaction mechanism between xanthate and pyrite,chalcopyrite was studied,the results show the formation of dixanthogen is the dominant factor but could not be the sole hydrophobic entity responsible for the flotation of pyrite and chalcopyrite.Corrosive electrochemistry results suggest that lime depresses sulfide minerals’ dissolver and the reaction between xanthate and pyrite is depressed resulting minerals can not be flotation.The electron structure of FeS₂（110）surface was computed by way of DFT and the process of electron transfer in sulfide flotation was simulated through ab-initio calculation and molecular dynamic simulation.The results show that electrons transfer from xanthate to the pyrites’ surface for intrinsic pyrite and xanthate adsorption on its surface is occurred.For sulfur vacancy pyrite,conducted band and valence band overlap,the surface of minerals have high electron and vacancy density,so the adsorption of xanthate on the sulfur vacancy pyrite is higher than that of intrinsic pyrite.For Fe vacancy pyrite,xanthate do not occur adsorption on its surface due to the high Fermi energy.Molecular dynamics simulation of the interaction between lime and pyrite indicate that both OH^- and CaOH⁺ can adsorb on pyrite surface,so pyrite was depressant with lime as regulator.更多还原