霸刀分享-钨的提炼过程
钨的提炼过程主要包括精矿分解、钨化合物提纯、钨粉和致密钨制取等步骤。以下是具体流程：
1. 精矿分解
钨精矿分解是将钨精矿转化为可溶性钨化合物的过程，常用火法和湿法两种方法：
火法分解：常用碳酸钠烧结法。将黑钨精矿和碳酸钠一起放置在回转窑内于800～900℃下烧结。处理白钨精矿时还需加入其他物质，目的是获得溶解度小的原硅酸钙，烧结温度约为1000℃。经约两小时的烧结，精矿分解率可达98～99.5%。烧结料在80～90℃下用水浸出，过滤后得钨酸钠溶液和不溶残渣。
湿法分解：利用有机溶剂将钨酸盐溶液中的钨元素分离出来，具有分离效果好、杂质去除彻底的优点；或利用离子交换法，利用离子交换剂将钨酸根离子吸附在交换剂上，再通过洗脱剂将其洗脱下来，实现钨元素的分离和纯化。
2. 钨化合物提纯
钨酸钠溶液所含硅、磷和砷等杂质在溶液中分别呈硅酸钠、磷酸氢钠和砷酸氢钠状态。煮沸溶液并用中和，当溶液pH为8～9时，硅酸钠水解成硅酸凝聚沉淀，加入和氯化铵溶液，使磷、砷生成溶解度很小的和砷酸铵镁沉淀除去。
3. 钨粉制取
常用的还原剂有氢气、碳等，还原过程需要在高温下进行，以获得高纯度的钨粉。
4. 金属钨制取
金属钨粉的制取是将还原得到的钨粉进行高温烧结，以得到致密的金属钨块。烧结过程需要在高真空或惰性气体保护下进行，以防止钨粉氧化。
5. 金属钨的提纯
金属钨的提纯通常采用化学提纯和物理提纯两种方法。化学提纯是通过化学反应将杂质去除，如酸洗、氧化、还原等；物理提纯则是通过物理手段如电解、真空蒸馏等将杂质去除。
以上就是钨的提炼过程，从精矿分解到最终得到高纯度的金属钨，每一步都需要精确的控制和处理。
The refining process of tungsten
The process of extracting tungsten mainly includes steps such as decomposition of concentrate, purification of tungsten compounds, production of tungsten powder and dense tungsten. Here is the specific process:
1. Decomposition of concentrate
The decomposition of tungsten concentrate is the process of converting tungsten concentrate into soluble tungsten compounds. Two methods are commonly used: pyrometallurgy and hydrometallurgy:
Pyrometallurgical decomposition: The sodium carbonate sintering method is commonly used. The black tungsten concentrate and sodium carbonate are placed in a rotary kiln at 800-900°C for sintering. When processing white tungsten concentrate, other substances are added to obtain the less soluble original calcium silicate, with a sintering temperature of approximately 1000°C. After about two hours of sintering, the decomposition rate of the concentrate can reach 98-99.5%. The sintered material is leached with water at 80-90°C, and after filtration, tungstate sodium solution and insoluble residue are obtained.
Hydrometallurgical decomposition: The tungstate salt solution is separated by using organic solvents, which has the advantages of good separation effect and thorough removal of impurities; or by using ion exchange method, the tungstate ion is adsorbed on the ion exchange agent, and then it is eluted with the eluent to achieve the separation and purification of tungsten elements.
2. Purification of tungsten compounds
The silicon, phosphorus and arsenic impurities contained in the sodium tungstate solution exist in the solution in the forms of sodium silicate, sodium hydrogen phosphate and sodium arsenite. After boiling the solution and neutralization, when the pH of the solution is 8-9, sodium silicate hydrolyzes into silicic acid and forms precipitates, and adding a solution of ammonium chloride, phosphorus and arsenic are converted into arsenic ammonium magnesium precipitates for removal.
3. Preparation of tungsten powder
Common reducing agents include hydrogen and carbon, and the reduction process needs to be carried out at high temperatures to obtain high-purity tungsten powder.
4. Preparation of metallic tungsten
The preparation of metallic tungsten powder is to conduct high-temperature sintering on the tungsten powder obtained from reduction to obtain a dense tungsten block. The sintering process needs to be carried out under high vacuum or in the presence of inert gas to prevent the tungsten powder from oxidizing.
5. Purification of metallic tungsten
The purification of metallic tungsten is usually carried out by two methods: chemical purification and physical purification. Chemical purification is achieved through chemical reactions to remove impurities, such as acid washing, oxidation, and reduction; physical purification is carried out through physical means such as electrolysis and vacuum distillation to remove impurities.
This is the process of extracting tungsten. From the decomposition of the concentrate to finally obtaining high-purity metallic tungsten, each step requires precise control and handling.