镍红土矿高压酸浸过程的金属元素浸出行为

以镍、钴的提取为目的,研究褐铁矿型镍红土矿高压酸浸过程中各金属元素的浸出行为,探讨硫酸加入量、浸出温度、浸出时间及液固比对各金属元素浸出率的影响.实验结果表明,在优化条件下Ni、Co、Mn和Mg的浸出率分别达到97%、96%、93%和95%以上,则Fe的浸出率小于1%.对高压浸出渣的分析表明,渣中的铁和硫主要分别以赤铁...     

从镍钼矿中提取镍钼的工艺

针对现行镍钼矿处理工艺存在的钼镍需要分别提取的缺陷,提出镍钼矿加钙氧化焙烧−低温硫酸化焙烧−水浸提取镍钼的新工艺。以贵州遵义镍钼矿为原料,对CaO加入量、氧化焙烧温度、氧化焙烧时间、硫酸加入量、硫酸化焙烧温度、硫酸化焙烧时间以及焙砂水浸工艺参数对镍钼浸出率的影响进行研究。结果表明：在最佳工艺条件下,钼的浸出率为97.33%,镍的浸出率为93.16%,且最佳工艺参数为100 g镍钼矿加入35 g CaO,700 ℃氧化焙烧2 h,得到的焙砂加入70 mL浓硫酸,再经250 ℃硫酸化焙烧2 h;硫酸化焙烧得到的焙砂按液固比2:1加水搅拌,经98 ℃浸出2 h。加入CaO不仅能有效减少镍钼矿氧化焙烧烟气对环境造成的污染,而且能显著提高镍的浸出率。     

镍钼矿酸浸液中磷钼存在形态的热力学计算

通过热力学计算25℃时 体系在水溶液中的离子形态并绘制其随pH、磷浓度变化的关系图。为了模拟镍钼矿硫酸浸出液的液相环境,控制模拟料液中钼的浓度在0.1mol/L左右,分析磷钼摩尔比(n(P):n(Mo))为1:1、1:9、1:12、1:50时其热力学平衡图的变化规律。结果表面：随着pH值的降低,钼的存在形态分别是钼酸根离子、磷钼杂多酸根离子和同多钼酸根离子。当氢离子浓度在0.1mol/L左右,随着溶液中磷浓度的降低,钼的存在形态由Dawson结构的 转变成Keggin结构的 。     

常压酸浸闪锌矿的条件对锌浸出率的影响

研究了在常压、通氧条件下 ,用浓硫酸浸取闪锌矿制取硫酸锌时酸浸条件对锌浸取率的影响。实验表明 ,当硫酸浓度为 40 % (质量比 ) ,液固比为 6～ 7∶1 (质量比 ) ,酸浸温度控制在 1 1 0～ 1 2 0℃ ,浸取时间为 2h ,氧流量为每升酸浸液 40～ 50cm3/min时 ,锌浸取率大于 95% ,闪锌矿中所含的硫大部分以单质硫析出。     

锌粉置换镓锗渣高压酸浸的浸出机理

研究锌粉置换镓锗渣的高压酸浸过程,考察硫酸浓度、液固比、浸出时间、浸出温度、助浸剂种类和添加量对Ga、Ge浸出率以及浸出渣过滤性能的影响。结果表明：增加硫酸浓度有利于Ga、Ge的浸出,但硫酸浓度超过156 g/L后,反而不利于Ge的浸出。浸出时间和温度对Ga、Ge浸出率影响较小,但增加浸出时间或提高反应温度均有利于改善浸出渣的过滤性能。添加硝酸钠或硝酸钙均可促进Ga、Ge的浸出,且硝酸钙的添加还可改善浸出渣的过滤性能。在硫酸浓度156 g/L、助浸剂硝酸钙60 g/L、液固比8、浸出温度150 ℃下浸出3 h,Ga、Ge浸出率可分别达到98%和94%以上,且浸出料浆过滤速度较常压酸浸时的提高近20倍。     

膜生物反应器浸出镍钼矿

采用对钼有一定耐受性的嗜热金属硫叶菌结合膜反应器浸出镍钼矿。结果表明：由于膜生物反应器（MBR）中膜的过滤作用,使浸出液中的钼浓度保持在该菌可以耐受的范围内,从而实现细菌对矿物相对高效的浸出。在矿浆浓度100mg/L、通气量1.0L/min下,将MBR浸出液中钼被控制在不同浓度,镍、钼的浸出率各不相同。当MBR浸出液中钼的浓度不超过395mg/L时,镍和钼的浸出率达到79.57%和56.23%;而在相同条件下的柱浸,镍、钼浸出率为75.59%和54.33%,低于相同条件下MBR浸出。     

直接酸浸-溶剂萃取法从废油加氢催化剂中回收钒和镍（英文）

采用直接酸浸-溶剂萃取法从废油加氢催化剂中选择性萃取分离钒和镍。钒(Ⅳ)和镍(Ⅱ)的萃取分离分为两步：钒和镍的酸浸以及溶剂萃取。首先,通过酸浸实现钒和镍的高效浸取,浸出率分别为88.07%和75.58%。其次,逆流萃取实验表明,在酸性环境下以P204作为钒的高效萃取剂进行三段萃取,钒的萃取率为99.21%,而镍和铁则不萃取。钒萃取余液经氨水-硫酸铵脱铝预处理后,在氨介质中以LIX84-Ⅰ作为镍的高效萃取剂进行三段萃取,镍的萃取率为99.79%。这种钒镍回收的工艺流程不仅可以实现钒和镍的分离回收,而且可以实现试剂的循环利用。     

空气氧化碱浸含砷钴镍渣

采用空气做氧化剂,在碱性体系中将砷、锌高效浸出。结果表明：在温度为80 ℃、碱浓度为5 mol/L、时间为12 h、液固比为5:1的条件下,砷、锌的浸出率均能够达到99%以上,2%的钴、铜被浸出,镍基本不被浸出;空气氧化浸出含砷钴镍渣的平均表观活化能为11.62 kJ/mol,属于扩散控制;平均反应级数为0.69;浸出渣中含铜68.24%、钴3.04%、镍0.87%,且含砷仅有0.01%,可进行铜、钴、镍的进一步回收。采用空气碱浸含砷镍钴渣,技术操作简单、成本低廉,避免剧毒砷化氢气体的产生,对含砷资源的综合利用有一定的现实意义。     

沉淀滴定法测定镍钼合金镀层和镀液中钼的含量

在乙酸盐缓冲溶液介质中，ＭｏＯ＾２－４与Ｐｂ＾２＋形成了水溶解的沉淀化合物，研究了该方法是在Ｎｉ＾２＋和其它金属离子存在下，用沉淀滴定法测定钼，以ＸＯ，ＣＰＢ为混合指示剂，Ｐｂ＾２＋标准溶液为滴定剂。终点变化额外敏锐。实验结果说明，各种阳离子均完全不干扰。已用于测定镍钼合金镀层，镀液中的钼含量，结果满意。     

Transformation and leaching kinetics of silicon from low-grade nickel laterite ore by pre-roasting and alkaline leaching process

The mineralogical phase transformation of a low-grade nickel laterite ore during pre-roasting process and the extraction of silicon during alkaline leaching process were investigated. The results indicate that the reaction activity of nickel ores is effectively improved by pre-roasting at 650 °C for 2 h, because of the transformation of lizardite into magnesium olivine and protoenstatite. When finely ground ore samples (44–61 μm) pre-roasted firstly react with sodium hydroxide solution (60 g/L) with a solid/liquid ratio of 1:5 at 140 °C for 120 min, the extraction of silicon can reach 89.89%, and the other valuable elements of magnesium, iron and nickel are accumulated in the solid residues. The leaching kinetics of nickel laterite ore can be described successfully by the diffusion through the product layer control model. The activation energy is calculated to be 11.63 kJ/mol and the kinetics equation can be expressed as 1–3(1–x)^2/3+2(1–x)=13.53×10^?2exp[–11.63/(RT)]t.     

Microwave assisted atmospheric acid leaching of nickel from laterite ore

The recovery of nickel from laterite ore with sulphuric acid under the effect of microwave irradiation was studied.The experimental results indicated that the extraction rate of nickel was influenced by reaction time,sulphuric acid concentration,and temperature,especially by microwave power.The results obtained from the experiments of orthogonal arrays showed that the optimum conditions of sulphuric acid concentration,reaction time,microwave power,and temperature were 25 vol.%,1.5 h,600 W,and 90°C,respectively.Under the optimal conditions,the nickel recovery could reach approximately 90.8%,which was higher than that obtained by conventional water bath heating.Kinetic experiments showed that the leaching of nickel in a sulphuric acid medium was controlled by chemical reaction occurring on the surface of laterite ore.The apparent activation energy was 38.9 kJ/mol.Microwave heating technology is efficient,clean,and easy to control and facilitate continuous processing of materials.     

Solvent extraction of molybdenum blue from alkaline leaching solution of the Ni-Mo ore

Molybdenum in the Ni-Mo ore was leached by air oxidation in an alkaline solution. Due to the high concentrations of SO₄²⁻, S₂O₃²⁻, SO₃²⁻ and AsO₄³⁻ in the solution, it was difficult to efficiently extract Mo by chemical precipitation or ion exchange process. So the extraction of Mo from the solution with the mixture of tertiary amine (N-235) and secondary caprylic alcohol dissolved in kerosene was investigated. The effects of several process parameters such as extractant concentration, feed solution pH, O/A ratio, temperature of extraction, and contact time were studied. Results proved that the extraction efficiency of Mo was 99.4% at pH 3, time 2 min and O/A ratio 1:4 with 15 v% N-235. Stripping of Mo with a 15 m% ammonia solution was essentially completed (99.9%) in a single stage at an O/A ratio of 3. Comparison of the chemical oxygen demand (COD) concentration of the feed solution (12,400 mg/L) and raffinate (8600 mg/L) indicated that the separation of Mo and reductive substances, such as S₂O₃²⁻ and SO₃²⁻, was achieved after solvent extraction. The Mo concentration in the strip liquor obtained in a single stage can be increased by contacting a new loaded organic phase. After repeated stripping, the concentration of Mo, As, P, W and V in the strip liquor were 125.82 g/L, 15.63 g/L, 0.73 g/L, 0.09 g/L, and 0.074 g/L respectively.     

Extraction of manganese and zinc from their compound ore by reductive acid leaching

Comprehensive utilization of low grade manganese–zinc compound ore containing lead and silver with a method of reductive acid leaching was studied. According to the ?–pH diagram of Mn–Zn–H₂O system, Mn and Zn can be leached simultaneously in the pH range of –2 to 5.61. The results showed that both hydrogen peroxide and sucrose were effective reductants which could intensify the simultaneous leaching of Mn and Zn into leachate as well as enrich Pb and Ag in the residue. 95.88% of Mn and 99.23% of Zn were extracted when the compound ore was leached with hydrogen peroxide in sulfuric acid media, meanwhile the contents of Pb and Ag in the residue were enriched to 13.21% and 489.36 g/t, respectively. When sucrose was used as the reductant, the leaching efficiencies of Mn and Zn separately achieved 98.26% and 99.62%, and contents of Pb and Ag in the residue were as high as 13.92% and 517.87 g/t, respectively.     

Pressure leaching of zinc silicate ore in sulfuric acid medium

Zinc silicate ore was characterized mineralogically and the results showed that zinc exists mainly as hemimorphite and smithsonite in the sample. Sulfuric acid pressure leaching of zinc silicate ore was carried out to assess the effect of particle size, sulfuric acid concentration, pressure, reaction time and temperature on the extraction of zinc and the dissolution of silica. Under the optimum conditions employed, up to 99.25% of zinc extraction and 0.20% silica dissolution are obtained. The main minerals in leaching residue are quartz and small amounts of undissolved oxide minerals of iron, lead and aluminum are associated with quartz.     

焙烧氟碳铈矿硫酸浸出稀土的动力学(英文)

研究了硫酸浸出德昌稀土与天青石共伴生矿的焙烧矿过程。考查粒度、搅拌速度、硫酸浓度和温度对稀土浸出率的影响,并对稀土的浸出动力学进行分析。在选定的浸出条件下:粒径0.074～0.100mm、硫酸浓度1.5mol/L、液固比8:1、搅拌速度500r/min,稀土浸出反应受内扩散控制,表观活化能为9.977kJ/mol。     

石煤钒矿硫酸活化常压浸出提钒工艺

研究石煤钒矿的硫酸活化提钒方法。分别考察矿石粒度、硫酸浓度、活化剂用量、催化剂用量、反应温度、反应时间和浸出液固比等因素对钒浸出率的影响。结果表明:石煤提钒的优化条件为矿石粒度小于74μm的占80%、硫酸浓度150 g/L、活化剂CaF2用量(相对于矿石)60 kg/t、催化剂R用量20 g/L、反应温度90℃、反应时间6 h、液固比(体积/质量,mL/g)2:1,在此优化条件下,钒浸出率可达94%以上;在优化条件下,采用两段逆流浸出,可有效减少活化剂CaF2以及浸出剂硫酸的消耗量;经过两段逆流浸出萃取反萃氧化水解工艺,全流程钒资源总回收率可达86.9%;V2O5产品纯度高于99.5%。