尿素造粒塔安全隐患的整改

简单介绍838#尿素造粒塔腐蚀状况,分析腐蚀原因并制定维修方案,以及组织施工的效果。     

尿素装置排放液中氨的回收

作者介绍了尿素装置停车后，造成排放液中氨的流失的原因及回收排放液中氨的措施。     

恒通化工尿素低压回收系统的操作控制

1低压回收系统流程 恒通化工股份有限公司尿素装置采用传统水溶液全循环法工艺，其低压段回收流程如图1。     

两步法合成2-氨基-5-硝基苯酚

以邻氨基苯酚和尿素为原料,将传统环合-硝化-水解三步法工艺改为环合硝化-水解两步法合成了2-氨基-5-硝基苯酚(ANP);研究了影响环合硝化反应和水解反应的因素;优化了反应条件。环合硝化反应的最优条件为:n(邻氨基苯酚)∶n(尿素)=1.00∶1.20、环合时间6h、硝酸用量40.2g、硫酸用量20g、硝化时间3h、硝化温度70℃,在此条件下中间产物6-硝基苯并噁唑酮的收率为90.2%;水解反应的最优条件为:体积分数95%的乙醇为溶剂、n(6-硝基苯并噁唑酮)∶n(氢氧化钠)=1.0∶3.3、水解温度80℃、水解时间15h,在此条件下ANP收率为81.2%。两步反应ANP的总收率为73.2%。对产品进行了元素分析和红外光谱表征,确认终产物为ANP。该方法成本低,ANP总收率高,溶剂可回收,三废量少。     

尿素国际市场价格全线上涨

9月上旬，国际尿素价格全线上涨，上涨幅度为10~40美元（吨价，下同）不等，目前已有美国海湾、委内瑞拉等各个市场的价格突破了300美元大关，最高的美国海湾地区到岸价，达到了360~363美元。与8月下旬相比，各市场的具体价格行情为：[第一段]     

小型尿素合成塔的腐蚀分析

本文论述了小型尿素合成塔的腐蚀机理,当前值街重视的几种腐蚀类型及保护措施。     

Nitrogen utilization and transformation in red soil fertilized with urea and ryegrass

The influence of fertilization with urea and ryegrass on nitrogen utilization and transformation in red soil has been studied by using ^15N tracer method.When urea and ryegrass were applied alone or in combination,the percentage of N uptaken by ryegrass from labelled urea was 3 and 1.7 times that from labelled ryegrass for the application rate of 200mgN.kg^-1 and 100mgN.kg^-1,respectively;combining application of ryegrass and ureareduced uptake of urea N and increased uptake of ryegrass N by ryegrass plant,but the percentage of N residued in soil increased for urea and decreased for ryegrass.when urea and ryegrass were applied alone,the percentage of N residued in soil from labelled ryegrass was more than 69% while that from labelled urea was less than 25%,and much more ryegrass N was incorporated into humus than urea N.     

磷酸一铵掺合尿素用于小麦的施用技术及肥效

磷酸一铵掺合尿素用于小麦的施用技术及肥效吴鲁智（登封市大冶镇农办４５２４７３）近年来，我们针对目前在小麦生产中出现的“无论水地旱地，一味追求施硝酸磷肥；不管土壤酸碱，一直施用磷酸二铵；不看化肥特性，碳铵与钙镁磷肥连年混用”的盲目施肥现象；大力开展了磷...