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.
2006, Vol. 23 
