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

1. <Dissolution mechanism of Tin and Zine in NaOH Solutions at elevated Temperatures and its application to scrap recycling of surface coated steel plates>研究了金属镀锡板在氢氧化钠水溶液中的溶解行为。在高于30 ℃的温度和高于0.1 mol/1·H2O的NaOH浓度下，溶解速率主要由溶解氧的扩散控制。随着温度的升高和转速的增大，反应速率增大，随着NaOH浓度的增大，反应速率达到最大值。这些结果应用于表面涂层钢板的回收处理. <Enhanced Dissolution of Copper in Cupric Ammine Solutions at elevated Temperatures and its application to removal of Cu from steel scraps.>金属铜板在铜氨溶液中的溶解速率在30 ℃以下主要受化学反应控制，在40 ℃以上主要受铜络合物扩散控制 ...更多信息 随着温度和转速的增加，它增加，而观察到的最大速率为增加Cu（II）浓度。不同阴离子对铜和铁的溶解速率有显著影响，碳酸根离子对铁有一定的缓蚀作用。根据实验结果，提出了一种从废钢中去除铜的方法. <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.>在K2O与Nb2O5的各种摩尔比（K/Nb）下，在40 ° C至200 ° C的范围内测量Nb 2O5的溶解度。Nb 205在K/Nb = 4/3的溶液组成下在给定温度下显示最大溶解度。随着温度的升高，Nb205在120 ℃以下的溶解度增加，在120 ℃以上的溶解度降低，在200 ℃时，Nb205的浸出率达到最大值，约为90%。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