Extracting gold from pyrite roster cinder by ultra-fine-grinding and resin-in-pulp

The ultra fine grinding and resin in pulp with pH value of 10 are used to extract gold from pyrite roster cinder. During leaching process, aluminium oxide ball is used as stirring medium, hydrogen peroxide as leaching agent and sodium hexametaphosphate as grinding agent. With AM 2б resin as absorber and sulfocarbamide as eluent, gold is recovered from cyanide pulp of pyrite roster cinder by resin in pulp. The effects of contact time, temperature and acidity etc. on the gold absorption are investigated by static methods and dynamic method respectively. The effects of flow rate of solution on dynamic adsorption and elution of gold are studied. The results show that AM 2б resin has good adsorbability in cyanide solution, and gold can be easily eluated from the loaded resin with 0.1mol/L hydrochloric acid and 1mol/L sulfocabamide. The adsorption rate and the elution of gold exceed 98%. When leaching time is 2 h, mass ratio of liquid to solid 4∶1, consumption of sodium cyanide 3 kg/t, concentration of hydrogen peroxide and sodium hexametaphosphate 0.05% respectively, adsorption time 30 min, temperature 10 30 ℃, volume of resin 3 mL, ratio of eluent to resin (10 20)∶1, velocity of eluent 1.5 mL/min, the leaching rate of gold reaches 85%. Compared with traditional leaching technology, it can reduce leaching time, avoid complex filter process, decrease sodium cyanide consumption and increase leaching rate of gold by 35%.

Ultra fine grinding of silver plant tailings of refractory ore using vertical stirred media mill

Ultra fine grinding of the plant tailings of a refractory silver ore was studied using a laboratory type vertical stirred media mill. Preliminary tests confirmed that ultra fine grinding substantially improves the extraction of silver from the tailings in cyanide leaching （i.e. 36% Ag extraction rate from the as-received tailings with d80 of 100 μm, c.f. 84% extraction rate after ultra fine grinding of the tailings with ds0 of 1.2 pro）. In the ultra fine grinding tests, the effects of ball diameter （2-4.5 mm）, stirring speed （200-800 r/m/n） and ball charge ratio （50%-80%） on the fineness of grind （ds0, ~tm） were investigated through a Box-Behnken design. Increasing stirrer speed and ball charge ratio decreased fineness of grind while larger balls resulted in the coarser products. The tests demonstrated that a fineness of grind less than 5 μm can be achieved under suitable conditions. Analysis of stress intensity indicated an optimum range of stress intensity of （0.8-2）× 10^- 3 μm for all power inputs.

Strengthening pelletization of manganese ore fines containing high combined water by high pressure roll grinding and optimized temperature elevation system

Pelletization is one of useful processes for the agglomeration of iron ore or concentrates. However, manganese ore fines are mainly agglomerated by sintering due to its high combined water which adversely affects the roasting performance of pellets. In this work, high pressure roll grinding(HPRG) process and optimization of temperature elevation system were investigated to improve the strength of fired manganese ore pellets. It is shown that the manganese ore possesses good ballability after being pretreated by HPRG twice, and good green balls were produced under the conditions of blending 2.0% bentonite in the feed, balling for 7 min at 16.00% moisture. High quality roasted pellets with the compressive strength of 2711 N per pellet were manufactured through preheating at 1050 °C for 10 min and firing at 1335 °C for 15 min by controlling the cracks formation. The fired manganese pellets keep the strength by the solid interconnection of recrystallized pyrolusite grains and the binding of manganite liquid phase which filled the pores and clearance among minerals. The product pellets contain high Mn grade and low impurities, and can be used to smelt ferromanganese, which provides a possible way to use imported manganese ore fines containing high combined water to produce high value ferromanganese.

EFFECT OF FINE GRINDING ACTIVATION ON LEACHING BEHAVIOUR OF SCHEELITE CONCENTRATE

The influence of mechanical activation on the leaching behaviour of scheelite was studied by means of fine grinding in an attritor and subsequently HCl leaching in presence of PO_4^(3-). Results showed that after fine grinding in the attritor,the reaction rate of scheelite with HCl-Na_3PO_4 solution was remarkably increased,the extraction of W increased from about 8 to 99%.The IR spectra and X-ray diffraction analysis indicated that in addition to an enlargement of surface area the fine grinding action had made also changes of fine struc- ture and reactivity of solid surface,hence the leaching process of scheelite can be carried out under mild leaching conditions.

Experimental Research on Performances of Dry-grinding Fine Cement for Grouting

The performances of dry grinding fine cement (DFC) in grouting procedure were experimentally studied.The measurement of its fineness and simulated test for injectability showed that this DFC could be used to inject rock mass with micro fissure.In order to improve the grouting quality,the water cement ratio and discarding time of slurry should be controlled precisely.If the water cement ratio is over 2∶1 in slurry that is made from DFC,it is not suitable to grout.Finally,the influence of different mixing times on strength of hydrated cement made from the DFC is explained by microstructure analysis with SEM.

Effect of grinding on chemical and physical properties of rice husk ash

The effect of grinding on the chemical and physical properties of rice husk ash was studied. Four rice husk ashes with different finenesses, i.e. coarse original rice husk ash （RHA0）, RHA1, RHA2, and RHA3 were used for the study. Ordinary Portland cement （OPC） was partially replaced with rice husk ash at 20% by weight of binder. The water to binder ratio （W/B） of the mortar was maintained at 110%±5% with flow table test. Specific gravity, fineness, chemical properties, compressive strength, and porosity test of mortars were determined. The differences in chemical composition of the rice husk ashes with different finenesses from the same batch are small. The use of RHA3 produces the mortars with good strength and low porosity. The strength of the mortar improves with partial replacement of RHA3 in comparison with normal coarse rice husk ash. The use of RHA3 results in a strong and dense mortar, which is due to the better dispersion and filling effect, as well as an increase in the pozzolanic reaction.

STIDU ON MACHANOCHEMIAL EFFECT OF POWDERY QUARTZ IN DRY AND WET GRINDING

Powdery quartz with average particle size of 10. 4 um which is a natural weathered quartz 'were ground in planetary ball mill. Variations of particle size distribution, specific surface area,crystal structure,facial amorphous and thermal character in dry grinding and wet grindding -were examined against grinding time. The results displayed that the fine grinding causes the structural disorder, facial amor-phism and the facial activity enhancing accompained by par-ticle size reduction as grinding proceeds > and the wet grind-ing lowered notably 'Grinding Limit'of the powdery quartz with this planetary ball mill.

The Recovery of Fine Cassiterite from Metasedimentary Rock

It is known that ore containing cassiterite （SnO2） has been our most important source of tin since antiquity and its successful separation continuously pose problems to mineral processors. The situation is more pronounced since the depletion of the more easily recoverable alluvial reserves forces us to work with the more complex deposits such as hardrock cassiterite ores. In order to understand more about the challenges in processing complex tin ore deposits, a metasedimentary rock ore sample from a mine in Malaysia was used in this study. Chemical analysis by wet method shows that SnO2 content in the sample was 2.86%, while for mineralogical analysis, the x-ray diffractogram （XRD） of the sample had identified that besides cassiterite, the sample also contained minerals such as quartz （SiO2） and clinochlore. Furthermore, the FESEM （field emission scanning electron microscope） micrograph analysis carried out on a polish section of the sample indicated that the fine cassiterite particles （approximately 80 ~tm） were found to be disseminated in the quartz minerals. Prior to the separation processes, grindability studies were carried-out on crushed samples to liberate the cassiterite from other gangue minerals and at the same time, avoid producing high percentage of fines. For the separation of tin from gangue minerals on the ground samples, two stages of gravity separations by shaking tables were carried out. The first stage was run on ground samples and for the second stage, the middling product from the first stage was re-tabled. Magnetic separation process on Concentrate 1 （stage 1） and Concentrate 2 （stage 2） products from the shaking table increased the grade of SnO2 to 46.85% and 61.90% respectively （as a non-magnetic products）. Further concentration process of these non-magnetic products by high tension separator, increased the grade of SnO2 from 85.05% to 98.77%.

镍钼矿选矿工艺分析

镍钼矿选矿是有价元素提取的关键过程,会为后续矿产资源开发奠定基础。本案例中的镍钼矿中镍含量为0.52%、钼含量0.74%,呈现出集合产出形态。为实现对矿产资源的良好开发,按照工艺流程脱质后,将CMC作为抑制剂,使用浮选工艺处理,选矿实验得到的镍、钼回收率,分别为81.22%、72.55%,有利于降低后续矿产焙烧投入的成本,提高镍钼矿冶炼效率。

超细粉碎联合半仿生技术处理的没食子残留物物理性质和生物活性分析

目的探讨经半仿生技术提取的没食子残留物(RTG)的物理性质和活性成分的变化,以及RTG的抗氧化能力。方法通过超细研磨机处理RTG,按颗粒粒径分为A组(<100µm RTG)、B组(100~300µm RTG)和C组(>300µm RTG),检测其水分、总灰分、水溶性、休止角、滑动角、崩溃角、体积密度、振实密度等物理特性;RTG经水和盐酸缓冲液的半仿生技术处理后,检测对人齿根膜韧带成纤维细胞增殖的影响及抗氧化能力。结果随着粒径的增加,RTG的水分含量显著降低(P<0.05),总灰分显著增加(P<0.05),体积密度显著升高(P<0.05),休止角、滑动角和崩溃角均显著降低(P<0.05),振实密度显著升高(P>0.05)。颗粒粒径相同时,RTG的水溶性随温度的升高而升高(P<0.05);温度相同时,水溶性随颗粒粒径的增加而减小(P<0.05)。盐酸缓冲液组总多酚含量显著高于水处理组(P<0.05),且A组显著高于B组和C组(P<0.05)。盐酸缓冲液组的OD510值显著高于水处理组(P<0.05);粒径越小,对细胞增殖作用越明显(P<0.05)。盐酸缓冲液组的DPPH、羟基自由基清除活性显著优于水处理组(P<0.05);粒径越小,RTG的抗氧化活性增加(P<0.05)。结论RTG再利用在生物技术产品开发方面具有巨大潜力,可为提高没食子的质量和临床应用提供理论依据。

新疆某含羟硅铍石矿分选实验

这是一篇矿物加工工程领域的论文。以新疆某次火山岩型铍矿石为研究对象,进行矿物组成、元素组成分析,查明有用矿物的嵌布粒度及赋存状态,并进行系统的浮选实验。在磨矿过程加入活化剂氟化钠,对磨矿细度、浮选药剂制度进行了优化,当磨矿细度为-0.074 mm 85%、pH值调整剂碳酸钠、抑制剂硅酸钠、捕收剂油酸钠用量分别为1500、1000、2000 g/t时,可以获得粗选精矿BeO品位6.03%、回收率97.02%的粗选指标。将粗选精矿再磨至-0.045 mm 90%,通过两次精选实验,精矿BeO品位达到8.40%,精矿BeO回收率为78.09%,粗选尾矿经过一次扫选实验,尾矿BeO含量可降至0.003%。“一粗一扫三精、中矿集中返回粗选”的浮选闭路实验,获得了精矿BeO品位8.12%、回收率80.99%的浮选指标,可以实现羟硅铍石的较好富集,满足我国当今铍冶炼工艺对原料BeO含量的要求。

超精密晶圆减薄砂轮及减薄磨削装备研究进展

在芯片制程的后道阶段,通过超精密晶圆减薄工艺可以有效减小芯片封装体积,导通电阻,改善芯片的热扩散效率,提高其电气性能、力学性能。目前的主流工艺通过超细粒度金刚石砂轮和高稳定性超精密减薄设备对晶圆进行减薄,可实现大尺寸晶圆的高精度、高效率、高稳定性无损伤表面加工。重点综述了目前超精密晶圆减薄砂轮的研究进展,在磨料方面综述了机械磨削用硬磨料和化学机械磨削用软磨料的研究现状,包括泡沫化金刚石、金刚石团聚磨料、表面微刃金刚石的制备方法及磨削性能,同时归纳总结了软磨料砂轮的化学机械磨削机理及材料去除模型。在结合剂研究方面,综述了金属、树脂和陶瓷3种结合剂的优缺点,以及在晶圆减薄砂轮上的应用,重点综述了目前在改善陶瓷结合剂的本征力学强度及与金刚石之间的界面润湿性方面的研究进展。在晶圆减薄超细粒度金刚石砂轮制备方面,由于微纳金刚石的表面能较大,采用传统工艺制备砂轮会导致磨料发生团聚,影响加工质量。在此基础上,总结论述了溶胶–凝胶法、高分子网络凝胶法、电泳沉积法、凝胶注模法、结构化砂轮等新型工艺方法在超细粒度砂轮制备方面的应用研究,同时还综述了目前不同的晶圆减薄工艺及超精密减薄设备的研究进展,并指出未来半导体加工工具及装备的发展方向。

基于BP神经网络的白云母超细磨工艺参数优化

为提高白云母超细磨的效率,采用皮尔森相关系数分析超细磨效率与各参数之间的敏感性,并建立BP神经网络模型对白云母的超细磨正交试验参数进行优化。研究结果表明:各参数对超细磨效率敏感程度由大到小依次为瓷球级配、搅拌速率、助磨剂种类、超细磨时间和助磨剂用量。利用BP神经网络优化后的工艺参数进行超细磨试验,可获得-13μm粒级质量分数为83.04%的白云母,与正交试验最佳点相比提高了2.19%,所建模型可提高白云母超细磨效率,且预测精度较高。研究结论为超细白云母粉体的高效制备提供参考。

水分对无烟煤破碎行为和研磨能耗的影响

煤中水分赋存形态和含量的变化会改变煤炭物理特性和孔隙结构,进而影响其破碎过程。为研究煤炭所含水分对其破碎行为的影响,以无烟煤为研究对象,利用加装功率测量装置的哈氏可磨仪模拟中速磨煤机内的破碎环境,对不同含水量煤样开展多时间批次的单独与混合破碎试验,并研究水分对煤炭破碎速率、煤粉细度及研磨能耗的影响。试验结果表明:相比于原始煤样,均化浸泡煤样单独破碎时初始粒级物料破碎速率因含水量的增加明显减小,其可磨性指数随水分增加先减小后增大,煤粉细度t10与含水量呈正相关关系。干、湿煤样混合破碎时13.34%含水量样品破碎速率和细粒级物料生成速率远大于相同水分的均化浸泡煤样,且其可磨性指数大于原煤;其他含水量的混配煤样可磨性指数略小于均化浸泡煤样,此差异随含水量增加而变大,而破碎速率和细粒级物料产率与均化浸泡煤样差别较小。经典能量—粒度关系模型可用来表征不同水分梯度样品单独和混合破碎过程,内、外水分不同程度降低了无烟煤抵抗破碎的能力,单独破碎时含水量增加可显著提高能量效率;将含水量参数引入能耗模型,实现对多梯度水分煤样破碎过程的表征。通过探究煤中含水量对煤炭破碎能耗的影响机理,揭示煤炭破碎过程中能量损失方式并为优化煤炭破碎工艺、降低能耗提供理论指导。

煤泥深度浮选脱灰提质增值化利用试验研究

炼焦煤煤泥经深度脱灰提质后的高品质精煤产品可作为1种优质的炼焦原料,从而有效实现对炼焦煤煤泥的增值化利用。拟以内蒙古某洗煤厂的炼焦煤煤泥为试验对象并进行浮选试验研究,探究不同磨矿细度、捕收剂和抑制剂对浮选试验结果的影响规律,以期优化浮选流程结构。结果表明,控制磨矿细度为<0.074 mm占97.12%,以M231作为捕收剂、D8211作为抑制剂,采用带有精扫选的“一粗-一扫-三精”浮选试验流程,针对煤泥特点与性质进行全流程闭路浮选试验而得到精煤和尾煤产品,其精煤灰分在12%以内,尾煤灰分在82%以上。精煤产品达到炼焦原料的要求,尾煤可以用作建材原料,可实现炼焦煤煤泥深度脱灰提质的增值化利用与高效回收。

打磨车间细颗粒物空间分布规律研究

为探求打磨车间自然通风条件下的细颗粒扩散分布规律,以打磨车间为研究对象,根据气固两相流理论,基于fluent软件,利用数值模拟方法模拟自然通风方式下打磨车间1~10 m的钢尘颗粒的空间分布规律。研究结果表明:模拟结果与实际数据相对比,偏差为5.54%~7.76%,吻合度高;在自然通风条件下,作业人员长时间停留处呼吸带高度的粉尘质量浓度高达10.69~14.91 mg/m3;钢尘自打磨面脱离后随风流向车间上部运移,粉尘在接触车间顶部后发生偏移部分粉尘被储物区的涡流、回流流场捕获;相邻打磨台之间存在流场叠加效应;细颗粒粉尘因车间内风流与外界交换效率低而长时间滞留在车间。该研究可为控制打磨作业粉尘浓度、避免因粉尘浓度过高而引起职业病危害,并为设计最优的除尘方案提供基础数据。

四川某深部难选矿工艺矿物学研究

为了开发利用地下深部矿物中铜、铁、锌等有用金属,采用MLA系统对四川某铜矿深部难选矿进行了工艺矿物学研究,分析了矿物的结构、组成、元素配分、嵌布特征及粒度分布,结果表明:矿物中铁元素的质量分数最高,达27.01%;深部矿物中铜、锌元素质量分数均高于浅部矿物,特别是锌元素,深部矿物较浅部矿物高出1.64%,而铜元素仅高出0.6%;原矿中主要金属矿物为磁黄铁矿,另有少量黄铜矿、铁闪锌矿;非金属矿物主要为石英,深部矿物中的黄铜矿质量分数比浅部矿物高出2.09%,铁闪锌矿质量分数高出2.71%;铜元素主要存在于黄铜矿中,达99.87%;铁元素主要存在于磁黄铁矿、黄铜矿、绿泥石和赤铁矿中,磁黄铁矿中的铁元素质量分数最高,达81.45%;锌元素主要存在于铁闪锌矿中,质量分数达99.53%。该矿石在-0.074 mm粒级占比为60%时,浮选铜、锌的效果最佳。磁黄铁矿和黄铜矿嵌布特征主要为单体解离形式,铁闪锌矿主要与其他矿物呈二元共生关系和三元包裹关系。矿物粒度主要分布在-1.2+0.424 mm区间,可通过磨矿实现完全解离。该研究成果可为该深部铜矿的高效开发提供理论指导。

山东某金矿工艺矿物学及选矿影响因素研究

山东某金矿金品位为1.4 g/t,属于低品位金矿。为有效回收该金矿中有价金属,对矿石进行工艺矿物学研究。研究结果表明,矿石中部分金矿物以自然金形式存在,部分金矿物以黄铁矿等硫化矿物为载体的包裹金形式存在。其中,以磁黄铁矿为载体的金矿物,由于单体解离度较低,天然可浮性较差,难以通过浮选回收,是导致金矿物损失的主要原因。实现以磁黄铁矿为载体的金矿物综合利用,有助于进一步提高金回收率,对该金矿进行浮选和尾矿磁选联合试验。试验结果表明:增加磨矿细度,可有效提高有用矿物单体解离度;浮选试验可将浮选尾矿中金、硫品位分别降低至0.35 g/t、0.48%;尾矿磁选作业可以将尾矿中金、硫品位分别降低至0.14 g/t和0.20%。研究结果可为同类型金矿床的开发和利用提供借鉴。

甘肃某金矿选矿试验研究

针对甘肃某金矿进行了浮选试验。试验采用碳酸钠为调整剂,硫酸铜为活化剂,丁基黄药+丁铵黑药为混合捕收剂,2号油为起泡剂,经过两次粗选、两次扫选、三次精选闭路试验,可获得金品位为251.27 g/t、金回收率为96.67%的精矿产品。该技术指标优异,为该类型金矿的选别提供技术依据。

国外某大型选矿厂矿石工艺矿物学特征及选矿工艺

铜是新能源时代不可或缺的重要金属,为高效开发国外某低品位铜矿石资源,鉴于工艺矿物学对矿石选矿工艺的重要作用,利用MLA、光学显微镜等测试分析技术,对该矿石开展了工艺矿物学研究,获得了重要的工艺矿物学资料,指导了选矿厂选矿工艺的确定。结果表明,矿石中主要金属硫化物为黄铜矿和黄铁矿,脉石矿物以石英、钾长石为主,其次为白云母、钠长石、黑云母等。含铜矿物基本为黄铜矿,少量的(蓝)辉铜矿和其他含铜矿物,在-74μm含量占62%的情况下,黄铜矿解离情况良好,粒度分布均匀,大部分集中在利于浮选回收的粒级范围内。该矿石在三次粗选、粗精矿分级再磨、三次精选、一次精扫选的选别处理下,当原矿含铜0.41%、含金0.24g/t,可获得铜精矿含铜20.83%、含金9.25g/t,铜回收率90.43%、金回收率68.60%的选矿指标。实现了低品位含金硫化铜矿石资源的高效开发利用。