Thermochemical properties of hydrothermal alkaline solutions and their application to metal extraction.

1. 本文研究了金属锡板在氢氧化钠水溶液中的溶解行为及其在表面涂覆钢板回收中的应用。溶解速率主要受溶解氧在温度高于30ºC和NaOH浓度高于0.1 mol/1-H20条件下的扩散控制。随着温度的升高和转速的增加，反应速率增大，随着NaOH浓度的增加，反应速率达到最大值。这些结果已应用于表面涂层钢板的回收处理。铜胺溶液中铜在高温下的增强溶解及其在废钢中脱除铜的应用。金属铜板在铜胺水溶液中的溶解速率主要受温度低于30ºC时的化学反应和温度高于40ºC时铜配合物的扩散控制。它随温度和转速的升高而增大，但Cu （II）浓度的增加速率最大。不同阴离子对铜和铁的溶解速率有显著影响，碳酸盐离子对铁的腐蚀有抑制作用。在此基础上，提出了一种废钢中铜的脱除方法。研究了铌酸盐中铌205的溶解度和铌酸盐在koh水溶液中的浸出行为，建立了铌和钽的碱热浸出工艺。在K20与Nb205的不同摩尔比（K/Nb）下，测定了Nb205在40 ~ 200 C范围内的溶解度。在一定温度下，当K/Nb=4/3时，Nb205的溶解度最大。温度升高导致Nb205的溶解度在120℃以下升高，在120℃以上降低。在200℃时，浸出率达到90%左右。试验证明，碱热浸出工艺是回收铌酸盐精矿中铌和钽的有效工艺。少

1. <Dissolution mechanism of Tin and Zine in NaOH Solutions at elevated Temperatures and its application to scrap recycling of surface coated steel plates>The dissolution behavior of metallic tin plate in aqueous sodium hydroxide solutions was investigated. The dissolution rate was mainly controlled by the diffusion of dissolved oxygen at temperatures higher than 30ﾟC and NaOH concentration higher than 0.1 mol/1-H20. It increase with the increase in temperature and in rotation speed, while a maximum rate was observed as incresing NaOH concentration. These results were applied to the recycling treatment of surface coated steel plates.2. <Enhanced Dissolution of Copper in Cupric Ammine Solutions at elevated Temperatures and its application to removal of Cu from steel scraps.>The dissolution rate of metallic copper plate in aqueous cupric ammine solutions was mainly controlled by chemical reaction at temperatures below 30ﾟC,and by diffusion of cupric complex at temperatures higher than 40 … More ﾟC.It increase with an increase in temperature and rotation speed, while a maximum rate was observed for increasing Cu (II) concentration. The effect of different anion showed significant results on dissolution rate of copper and iron, and carbonate ion was found to prevent the corrosion of iron. From the result, a method to remove Cu from steel scraps was proposed.3. <Solubility of Nb205 and leaching behaviors of Nb and Ta from niobite in KOHsolutions have been investigated in order to develop an alkali hydrothermal leaching prcess of Nb and Ta.>The solubility of Nb 205 was measured in the range of 40ﾟC to 200ﾟC at various molar ratios (K/Nb) of K20 to Nb205. Nb205 shows the maximum solubility at the solution composition of K/Nb=4/3 at a given temperature. The rise of temperature causes the solubility of Nb205 to increase at the temperatures below 120ﾟC,but decrease above 120ﾟC.The maximum leaching degree of about 90% was obtained at 200ﾟC.It was proved that the alkali hydrothermal leaching process is effective for the recovery of Nb and Ta from the niobite concentrate. Less