低硫化物浅成热液金矿床地球物理特征及勘探方法

低硫化物浅成热液金矿床是全世界许多矿业公司的勘探对象。它们往往产在一组石英脉中并以此为中心形成蚀变包壳 ,成矿温度 15 0℃2 5 0℃。矿化作用及有关蚀变使主岩中的磁铁矿被破坏产生退磁作用 ,并形成诸如冰长石、伊利石、明矾石等含钾矿物。蚀变带分布面积有时达数平方公里 ,可利用高分辨率航空磁测及放射性测量探测到。一些典型的低硫化物浅成热液矿床具有独特的地球物理特征 ,且这些特征与成矿后覆盖层及矿化带的侵蚀程度有关 ,因此综合地球物理方法是勘查此类矿床(特别是隐伏半隐伏矿床 )

甘肃某低硫化物金矿选矿试验研究

甘肃某金矿为贫硫化物石英脉型含金矿石,主要金属矿物为黄铁矿,金为矿石中唯一有价元素,金品位为2.82g/t,矿石中的金主要分布在自然金和硫化物中。根据矿石性质特点,该矿石适宜采用重—浮联合流程对金矿物进行回收。针对矿石,分别进行了磨矿细度、调整剂种类、捕收剂种类等条件试验,在此基础上进行了闭路试验。结果表明,通过重选可以获得金品位为3643.28g/t、金回收率为38.60%的高品位金精矿;通过一粗两精两扫的浮选工艺流程,可以获得金品位为55.55g/t、金回收率为55.91%的浮选金精矿,金总回收率为94.51%,矿石中的金得到了充分的回收利用。该工艺流程简单,对矿石的适应性强,选矿指标优良,产品多元化,高品位金精矿可直接通过火法炼金,提高企业经济效益。

贵州某金矿石可选性试验研究

针对贵州某低硫化物含金矿石开展了系统的可选性试验研究,考察了磨矿细度、调整剂、捕收剂等影响因素,确定了合理的选别流程。结果表明:在最佳试验条件下,闭路浮选试验可获得产率3.45%、金品位73.19 g/t、金回收率95.61%的金精矿,指标较好。该研究结果可为低硫化物含金矿石的可选性评价和开发利用提供重要的技术参考依据。

地质勘探管爆裂分析

采用化学分析和金相检验等方法,对地质勘探管爆裂原因进行了分析,结果表明:硫偏析以及低熔点硫化物是造成其爆裂的主要原因。

Catalytic effect of activated carbon on bioleaching of low-grade primary copper sulfide ores

The catalytic effect of activated carbon on the bioleaching of low-grade primary copper sulfide ores using mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was investigated. The results show that the addition of activated carbon can greatly accelerate the rate and efficiency of copper dissolution from low-grade primary copper sulfide ores. The solution with the concentration of 3.0 g/L activated carbon is most beneficial to the dissolution of copper. The resting time of the mixture of activated carbon and ores has an impact on the bioleaching of low-grade primary copper sulfide ores. The 2 d resting time is most favorable to the dissolution of copper. The enhanced dissolution rate and efficiency of copper can be attributed to the galvanic interaction between activated carbon and chalcopyrite. The addition of activated carbon obviously depresses the dissolution of iron and the bacterial oxidation of ferrous ions in solution. The lower redox potentials are more favorable to the copper dissolution than the higher potentials for low-grade primary copper sulfide ores in the presence of activated carbon.

Adsorption of dimethyl trisulfide from aqueous solution on a low-cost adsorbent:thermally activated pinecone

Thermally activated pinecone(TAP) was used for the adsorption of dimethyl trisulfide(DMTS)from aqueous solutions,which was proved to be the main odorous in algae-caused black bloom.The effects of adsorbent dosage,adsorbate concentration and contact time on DMTS biosorption were studied.The TAP produced at 600℃ exhibited a relatively high surface area(519.69 m^2/g) and excellent adsorption capacity.The results show that the adsorption of DMTS was initially fast and that the equilibrium time was6 h.Higher initial DMTS concentrations led to lower removal percentages but higher adsorption capacity.The removal percentage of DMTS increased and the adsorption capacity of TAP decreased with an increase in adsorbent dosage.The adsorption process conforms well to a pseudo-second-order kinetics model.The adsorption of DMTS is more appropriately described by the Freundlich isotherm(R^2=0.996 1) than by the Langmuir isotherm(R^2=0.916 9).The results demonstrate that TAP could be an attractive low-cost adsorbent for removing DMTS from water.

Separation of sulfide lead-zinc-silver ore under low alkalinity condition

A complex lead-zinc-silver sulfide ore containing 2.98% Pb, 6.49% Zn and 116.32×10^-4 % Ag （mass fraction） from Yunnan Province, China, was subjected to this work. Research on mineral processing was conducted according to the properties of the lead-zinc-silver ore. Under low alkalinity condition, the lead minerals are successfully separated from the zinc minerals with new reagent YZN as zinc depressant, new reagent BPB as lead collector, CuSO4 as zinc activator and ethyl xanthate as zinc collector. The associated silver is mostly concentrated to the lead concentrate. With the process utilized in this work, a lead concentrate of 51.90% Pb with a recovery of 82.34% and a zinc concentrate of 56.96% Zn with a recovery of 81.98% are produced. The silver recovery in the lead concentrate is 80.61%. Interactions of flotation reagents with minerals were investigated, of which the results indicate that the presence of proper amount of Na2S can precipitate Pb^2＋ and has a sulfidation on oxidized lead minerals. The results also show that NazCO3 and YZN used together as combined depressants for sphalerite can signally improve the depressing effect of new reagent YZN on sphalerite.

Bioleaching of low-grade copper sulfide ores by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans

The grown conditions of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were investigated,and then experiments were conducted to research the bioleaching behaviors of crude ore of copper sulfide and hand-picked concentrates of chalcopyrite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans.The experimental results show that the bacteria grow best when the temperature is(30±1) °C and the pH value is 2.0.The bacteria concentration is 2.24×107 mL-1 in this condition.It is found that the copper extraction yield is affected by the inoculum size and the pulp density and the extraction yield increases as the inoculum size grows.The bioleaching rates reach their highest point in sulfide copper and chalcopyrite with a pulp density of 5% and 10%,respectively.Column flotation experiments of low-grade copper sulfide ores show that the bioleaching recovery reaches nearly 45% after 75 days.

广西融水县大坡岭锡多金属矿床地质特征及成因

大坡岭锡多金属矿床位于三防岩体东侧,矿体呈透镜状、脉状赋存于橄辉岩体及四堡群鱼西组(Pt2y)石英片岩中,受层位和NNW、NE向断裂构造控制明显。锡多金属成矿作用与雪峰期花岗岩有着密切的时空关系。雪峰期花岗岩形成时代为836 Ma~700 Ma,锡石硫化物期生成时代为800 Ma~717Ma,两者形成时代较为吻合。据矿物共生组合、围岩蚀变等地质因素综合分析,矿床成因类型为中—低温热液锡石硫化物型矿床。

Lattice Mismatch Induced Tunable Dimensionality of Transition Metal Dichalcogenides

Low-dimensional materials have excellent properties which are closely related to their dimensionality.However,the growth mechanism underlying tunable dimensionality from 2D triangles to 1D ribbons of such materials is still unrevealed.Here,we establish a general kinetic Monte Carlo model for transition metal dichalcogenides(TMDs) growth to address such an issue.Our model is able to reproduce several key findings in experiments,and reveals that the dimensionality is determined by the lattice mismatch and the interaction strength between TMDs and the substrate.We predict that the dimensionality can be well tuned by the interaction strength and the geometry of the substrate.Our work deepens the understanding of tunable dimensionality of low-dimensional materials and may inspire new concepts for the design of such materials with expected dimensionality.

Efficient and stable all-inorganic Sb_(2)(S,Se)_(3)solar cells via manipulating energy levels in MnS hole transporting layers

The use of organic hole transport layer(HTL)Spiro-OMeTAD in various solar cells imposes serious stabil-ity and cost problems,and thus calls for inorganic substitute materials.In this work,a novel inorganic MnS film prepared by thermal evaporation has been demonstrated to serve as a decent HTL in high-performance Sb_(2)(S,Se)_(3)solar cells,providing a cost-effective all-inorganic solution.A low-temperature air-annealing process for the evaporated MnS layer was found to result in a significant positive effect on the power conversion efficiency(PCE)of Sb_(2)(S,Se)_(3)solar cells,due to its better-matched energy band alignment after partial oxidation.Impressively,the device with the optimized MnS HTL has achieved an excellent PCE of about 9.24%,which is the highest efficiency among all-inorganic Sb_(2)(S,Se)_(3)solar cells.Our result has revealed that MnS is a feasible substitute for organic HTL in Sb-based solar cells to achieve high PCE,low cost,and high stability.