【摘要】 利用尿素和硫化氢等原料制备硫脲,提出了尿素-氰氨化钙法新工艺。首先,用尿素和氧化钙、氢氧化钙和碳酸钙制备氰氨化钙,再用硫化氢和氢氧化钙制备硫氢化钙,最后用氰氨化钙与硫氢化钙反应,并采用冷冻结晶法精制硫脲,产品符合国家标准。且其产率比传统工艺高出5%~10%。更多还原

【Abstract】 A new process,urea-calcium cyanamide method,for producing thiourea from urea and hydrogen sulfide is proposed.Calcium cyanate is prepared from urea and cium cyanamide and hydrogen sulfide.Thiourea is refined by freezing crystallite.The experimental results indicated that by this process,the production can reach the standard of country,and the yield is 5%—10% more than that of the old process.更多还原