方铅矿的直接还原研究SCIEI

在873—973K的温度范围内研究了方铅矿的氢还原反应·结果表明,反应比较彻底,其规律可用在化学控制区的收缩核模型描述.还原反应为氢浓度的一级反应,活化能为79.0kJ/mol.试样的SEM二次电子图象表明,因液态 Pb与固态方铅矿间的界面张力很大,反应过程中在方铅矿表面难以形成Pb的液膜。     

Physical chemistry mechanisms of CDR system in sulphide mineral flotation

The flotation tests,zeta potential measurements,and Fourier transform infrared spectroscopy(FTIR) analysis on galena,sphalerite,and pyrite were studied in a collecting-depressing-reactivating(CDR) system.In this system,sulphide minerals were first collected and acti-vated by the collector,and then depressed strongly by Ca(OH)2 in a strong alkaline solution.Finally,they were reactivated by H2SO4.The flotation tests of pure minerals showed that in the Ca(OH)2 depressing process sulphide minerals had similar flotation characteristics because they had already been influenced by the collector.Hence,the flotability differences between them were reduced.However,in the H2SO4 re-activating process considerable differences in the flotability between galena and sphalerite/pyrite were produced.That is to say,galena was relatively easy to be reactivated by H2SO4,but sphalerite and pyrite were not reactivated at pH 11.The zeta potentials of sulfide minerals measured by the Zeta Plus presented irreversible characteristics on the change of pH values.The results of the FTIR spectra analysis indi-cated that the collectors already adsorbed on the mineral surface were removed partially by Ca(OH)2.     

复杂铅锑银锌多金属硫化矿浮选分离工艺研究

针对广西复杂铅锑银锌多金属硫化矿,在工艺矿物学研究的基础上,进行了“铅锑银优先混浮-锌硫混浮及分离”和“铅锑银硫混浮及分离-锌浮选”工艺流程的对比研究。结果表明,在弱抑制条件下,采用硫酸锌 亚硫酸钠作抑制剂,乙硫氮作捕收剂,“铅锑银硫混浮及分离-锌浮选”工艺流程可实现铅锑银硫与锌的有效分离;铅锑银硫混合精矿经再磨处理,采用少量石灰作抑制剂,可实现铅锑银与硫的有效分离;闭路试验获得了含铅67.80%、含银2606.17 g/t、含锑5.01%的铅精矿,铅、银、锑回收率分别为91.08%、77.46%和62.42%;含锌51.40%、含银295.48 g/t的锌精矿,锌、银回收率分别为87.29%和6.55%;含硫49.95%的硫精矿,硫回收率41.29%。     

Technological condition in slurry electrolysis of high-silver galena concentrate

Effects of various technological conditions such as ρ(C1^- ), ρ(Fe)T, pH value and temperature on the cell voltage, lead leaching rate and the cathodic current efficiency of the slurry electrolysis of high-silver galena concentrate were studied, and the behavior regularity of lead and silver was investigated. As a result, the suitable condition was determinedas, ρ(C1^-)230g/L, ρ(Fe)T15g/L, pH 1, temperature 70℃, electrolysis time 6h. Under such condition,adopting the cathodic current density of 150 A/m2 and the liquid-solid ratio of 15 : 1, lead powder with a purity degree of 91. 18% was got. At the same time, leaching rate of lead, leaching rate of silver and cathodic current efficiency amounted to 96.88%, 70.88% and 75.68% respectively.     

Galena-pyrolusite co-extraction in sodium chloride solution and its electrochemical analysis

The co-extraction behavior of galena-pyrolusite in a sodium chloride solution and the electrochemical mechanism of this process were investigated, and some factors affecting the leaching rate of Pb and Mn were optimized. The results show that all the factors such as the concentration of NaCl, HCl and pyrolusite ore, reaction time, temperature, adding times of HCl, affect the leaching rate of Pb. The main affecting factors are the concentration of NaCl, reaction time and temperature. The Tafel polarization curves and EIS plots of the galena and pyrolusite in the NaCl solution demonstrate that during the oxidation process of galena mineral electrode, film forms on the galena surface, which prevents galena from deeper oxidation. However, the film resistance can be greatly reduced in the presence of sodium chloride, thus promoting the reaction rate of galena.     

Correlation between surface free energy and floatability of galena with potassium ethyl xanthate

From the maximal extrapolated film pressure π_max values for n-octane and n-propanol, the dispersion and non-dispersion components of the surface free energy of galena precoated with potassium ethyl xanthate (collector) were estimated and they were then correlated with the floatability of galena. The collector layer deposited by methanol evaporation did not produce any significant changes in the surface free energy of galena. Polymolecular adsorption of the collector occurred from aqueous solution. The adsorbed collector layer of ~8 statistical monolayers in thickness produced a considerable decrease in the dispersion component of the surface free energy and complete disappearance of non-dispersion interactions. At this surface coverage, a certain change in the properties of the adsorbed layer appeared which was probably connected with the formation of polymolecular layers containing dixanthogen. The work of the water adhesion being significantly lower than the work of water cohesion appeared insufficient to achieve a high floatability of galena.     

Kinetics of electrochemical process of galena electrode in diethyldithiocarbamate solution

1　ＩＮＴＲＯＤＵＣＴＩＯＮＤｉｅｔｈｙｌｄｉｔｈｉｏｃａｒｂａｍａｔｅ (ＤＤＴＣ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｆｒｅｑｕｅｎｔｌｙｕｓｅｄｃｏｌｌｅｃｔｏｒｓｆｏｒｆｌｏｔａｔｉｏｎｏｆｈｅａｖｙ ｍｅｔａｌｓｕｌｆｉｄｅｍｉｎｅｒａｌｓ ,ｓｕｃｈａｓｇａｌｅｎａ ,ｃｈａｌｃｏｐｙｒｉｔｅａｎｄｊａｍｅｓｏｎｉｔｅ ,ａｎｄｉｔｓｈｏｗｓｓｔｒｏｎｇｓｅｌｅｃｔｉｖｉｔｙ[1] .ＷｈｅｎＤＤＴＣｗａｓｕｓｅｄｉｎｈｉｇｈｌｙａｌｋａｌｉｎｅ (ｐＨ >11.4 )ｆｏｒｓｅｐａｒａｔｉｎｇｇａｌｅｎａｆｒｏｍｓ…     

综合回收锌矿石中伴生低品位铜铅工艺研究

某锌矿石中伴生有铜、铅等矿物,其中锌品位为3.29%、铅品位为0.084%、铜品位为0.11%,为原生硫化矿石。根据矿石性质采用铜铅混合浮选—铜铅分离—锌浮选的工艺流程,进行了小型试验和工业试验,采用BK510抑铜浮铅工艺,工业试验指标与原重铬酸钾工艺流程指标比较,铅精矿品位由38.08%提高到60.59%,铅回收率由30%提高到45.20%,铜精矿品位由20%提高到21.43%,铜回收率由34%提高到40.04%,获得可观的经济效益。     

Collector matching in origin potential flotation

Through thermodynamic calculation and electrochemistry analysis~ taking the galena as example,the ba-sis for collector matching in origin potential flotation (OPF) was studied. The results of thermodynamic calculation show that the upper limit value of pH and flotation potential of diethyldithiocarbamate (DDTC) is higher than that of xanthogenate (KBX), which indicates that the collecting ability of DDTC for galena is better than that of KBX.The results of the interface capacitance analysis show that lead diethyldithiocarbamate (PbD2) is more steady than lead xanthogenate (Pb(BX)2) on the galena surface under the oxidation condition; the resistance analysis shows thatD2 (DDTC oxidizes into its dimmer) and dixanthogen (BX)2 will occur non-faradic desorption on the pyrite electrodesurface when the potentials are above 0.13 V and 0.2 V respectively. A synthetical criterion ΔE of collecting ability and selectivity was proposed. The results predicted by this criterion are confirmed through flotation experiments of ore.     

二氧化锰浸出方铅矿工艺条件的正交法优化

用正交实验法优化了在盐酸体系中二氧化锰浸出方铅矿精矿的工艺参数。直接分析和方差分析结果表明: 5种工艺参数对铅浸出率影响由大到小的顺序为: 反应体系中总液体与总固体质量比m_总液/m_总固, 二氧化锰与方铅矿精矿质量比m_二氧化锰/m_方铅矿, 盐酸浓度, 反应时间, 反应温度。最佳实验方案组合为:m_总液/m_总固=10、m_二氧化锰/m_方铅矿=1.3、盐酸浓度为3 mol/L、反应时间为60 min、反应温度为80 ℃, 该组合能使方铅矿精矿中的铅浸出率大于99.5%。