汽车碳纤维饰品湿碳手工成型工艺关键参数分析

汽车湿碳手工成型工艺生产效率低,因此,文章对树脂胶固化温度和保温时间两个关键参数进行了探讨,应用阿伦尼乌斯方程,分析树脂胶反应速率与温度之间的关系,揭示了反应速率随着温度的提高而增加。在此基础上,制备了碳纤维树脂胶,并通过四组不同实验设置,确定了最佳的关键参数值。实验结果表明,当固化温度设置为80℃时,固化时间需4~5 min,但产品表面气泡尺寸和密度较大;而将温度降至70℃,固化时间增至5~6 min时,气泡尺寸和密度有所减小;在60℃时,固化时间为8~10 min,产品表面气泡尺寸和密度进一步减小;若温度降至40℃,固化时间需22~25 min,此时产品表面气泡尺寸和密度最小。综合考虑成本和质量因素,研究推荐的最佳参数值为固化温度60℃,保温时间9 min,对提高汽车湿碳饰件的生产效率具有一定参考意义。

Study on hydrometallurgical process and kinetics of manganese extraction from low-grade manganese carbonate ores

In order to utilize low-grade manganese ore resources effectively, a hydrometallurgical process was developed for manganese extraction in dilute sulfuric acid medium, and the kinetics of leaching manga- nese was also investigated. At room temperature, manganese from low-grade manganese carbonate ores was extracted by sulfuric acid leaching without reductants. During the extracting process, single-factor analysis method was used to evaluate the effects of grinding fineness, sulfuric acid concentration, liquid-to-solid ratio, agitation rate and leaching time on the leaching efficiencies of Mn and Fe. The optimal leaching conditions are determined as coarse particles of below 2 mm size （without ball-milling）, sulfuric acid concentration of 0.86 mol/L, liquid-to-solid ratio of 5：1, agitation rate of 150 r/rain and leaching for 180 min at room temperature. Under the optimal conditions, the leaching efficiencies of Mn and Fe are 96.21g and 13.35%, respectively. In addition, through the experiments at different temper- atures, it is found that the leaching process follows the shrinking core model under the conditions of changing acid concentration and intermittent reaction device. Moreover, the apparent activations of effective diffusion and chemical reaction in the kinetic model are calculated to be 18.83 and 27.15 kJ/mol, respectively.