尿基复合肥K-T工艺技术分析

介绍尿基复合肥K T技术工艺流程;通过造粒、系统温度控制、缩二脲含量控制、重钙的氨化、除尘洗涤系统、配料系统等方面的技术特点、操作控制要点的分析,指出K T工艺生产高氮复合肥的突出优势。     

我国最大规模重钙生产线的设计分析

通过我国最大规模８０万吨／年重钙生产线的引进，介绍了英国ＨｙｄｒｏＡｇｒｉ专利商料浆法生产重钙的技术概况、工艺流程设计特点以及主要工艺控制参数。并介绍了该装置的重钙试验报告。     

重质碳酸钙粉磨设备及工艺

详细介绍了重质碳酸钙的应用、工艺及粉磨设备的基本情况,着重介绍了生产５～２５μｍ重钙的干法粉磨设备及工艺和生产造纸涂布级９０％以上小于２μｍ重钙的湿法粉磨设备及工艺。另外探讨了重钙的粒度测定。     

料浆法重钙试生产经验探讨

现市场上销售的重钙主要是采用传统法工艺生产，其主要工艺缺陷在于占地面积大、运转设备多、工艺流程长、投资大等。而采用料浆法工艺流程生产，不仅节约了熟化和配料的场地投资，关键的是缩短了工艺流程，便于集中控制，同时节约了大量的人力物力。     

铜陵有色金冠铜业奥炉项目制酸系统生产实践

介绍了铜陵有色金冠铜业奥炉项目760 kt/a铜冶炼制酸系统的设计和生产运行情况。制酸系统稀酸洗涤净化采用一级动力波洗涤塔—填料洗涤塔—二级动力波洗涤塔—两级电除雾器工艺流程,转化换热采用ⅢⅠ-ⅣⅡ"3+1" 4段转化流程。针对实际生产中遇到的问题采取相应改进措施后,装置各项技术经济指标良好,SO_2转化率达到99.91%以上,二吸塔出口烟气ρ(SO_2)400 mg/m~3。     

重钙装置改产磷铵反应与尾气洗涤系统设备出现的问题

介绍瓮福磷肥厂重钙(TSP)装置改产DAP后,反应与尾气洗涤系统料浆泵、搅拌器、反应器、洗涤泵、重要阀门在运行中出现的问题及处理措施.     

新型絮凝剂对提高磷酸产量和降低消耗的作用

由于高品位磷矿的紧缺,磷酸生产的过滤成为生产的瓶颈,为提高过滤强度,方法之一是加絮凝剂。介绍加絮凝剂的磷酸过滤工艺流程;絮凝剂的选用方法及应避免的误区;SC-3450絮凝剂的应用效果:萃取率提高1.25%,洗涤率提高3%,磷矿、硫酸等消耗降低,磷酸产量提高。     

浅议瓮福重钙厂80万吨/年重钙装置的选择

本文探讨了选择重钙生产装置的依据,比较了三种重钙生产工艺的优缺点,提出了瓮福磷肥厂80万吨/年重钙生产装置选择的意见,即选用二个系列、以矿浆浓密后采用料浆法生产重钙。     

改性重钙的研制及其在复混肥生产中的应用

由于重钙的特性,用作生产复混肥的磷源,必须中和其游离酸。文中介绍重钙改性剂的选择与适宜用量的试验,以重钙量的5%～10%为宜;改性后重钙的企业标准。用改性后的重钙生产多种规格三元复肥应有表面包裹装置,以防吸湿。     

浅谈磷矿的反应活性对重钙生产的影响

结合大峪口矿肥结合工程，重点阐述重钙生产对原料的要求。磷矿的反应活性是影响重钙生产的一个重要因素，由于我国磷矿反应活性很低，大峪口项目重钙生产采和浓酸固化法。     

重过磷酸钙产品的推广和应用

重过磷酸钙是由磷酸分解矿粉后得到的高浓度磷肥,是重要的磷肥品种。重过磷酸钙可直接施用,也可作为制造其它三元肥料的原料。本文全面回顾上海化工研究院在重钙的研制工作中所取得的成果,并对今后有关重钙相关技术的开发提出了有益的设想和建议,以期推动重钙生产的进一步发展。     

Mass and energy flows in a fluoride scrubber when the fluoride is returned to single superphosphate

The gaseous fluoride evolved during the production of single superphosphates may be disposed of by scrubbing it from the effluent gas streams with water sprays and using the resulting scrubber liquors as sources of dilution water for the concentrated sulphuric acid used in the superphosphate manufacturing processes.Part of the returned fluoride is re-evolved which leads to higher fluoride loadings on the scrubbing systems which must therefore be relatively large and expensive installations. Accurate initial design is thus important to minimise the costs involved.This paper presents a theoretical model of such a zero effluent discharge system which will aid in this process. Parameters covered include the temperatures of the gases and liquids within the scrubbing system, the amount of fluoride re-evolved from the superphosphate and the vapour pressures of fluoride over the scrubber liquors.The effects of increasing the number of scrubbing stages while keeping the total number of transfer units constant and varying the air flows within scrubbing systems have been calculated and the results are presented.     

流化造粒生产非均质尿基复合肥

简要介绍了流化造粒生产高浓度非均质尿基复合肥新工艺的开发和试验过程，结果表明可采用磷酸 一铵、磷酸二铵、普钙或重钙等原料生产尿基复合肥，养份可根据用户需求进行调整。在普钙和重钙颗粒 上喷涂熔融尿液生产的尿基复合肥还能防止吸湿。     

利用部分过磷酸钙为磷源喷涂和氨化造粒法生产多品种硫基复合肥的工艺研究

介绍以过磷酸钙或重钙为部分或全部磷源,生产多品种,低、中、高浓度硫基复合肥的工艺原理,流程,设备选型,工艺指标,技术要点。该工艺已在很多工厂实施,运行效果很好。     

100kt/a重钙生产装置扩能技改措施

探讨国产化重钙生产装置的生产工艺及设备局部整改,主要是用较省的投资实现产能的最大化。     

Effectiveness of partially acidulated phosphate rock as a source to plants in calcareous soils

In a series of greenhouse experiments granulated phosphate fertilizers prepared by mixing triple superphosphate with phosphate rock and partially acidulated phosphate rock, ranging in their content of water souble P from 95 to 17 per cent of total P were applied to neutral and slightly alkaline (pH 6.9–7.8), sandy loam to clay soils ranging in calcium carbonate content from 2 to 35 percent. Dry matter yield of clover, alfalfa, millet or maize were obtained, P uptake determined and sodium bicarbonate extractable P in soil measured. In one field experiment triple superphosphate was compared to mixture of triple superphosphate and phosphate rock on maize. X ray difraction on one triple superphosphate — phosphate rock mixture and on one partially acidulated phosphate rock showed that both fertilizers contain mainly monocalcium phosphate and fluorapatite. After incubation in soil the dicalcium phosphate content rose and the monocalcium phosphate disappeared.Parameters received in greenhouse experiments and in the field indicate that phosphate fertilizers composed of superphosphate and up to 50 percent phosphate rock are as efficient source of P to plants on calcareous and slightly alkaline soils as superphosphate. If this indication would be proven in extensive field experimentation it would lead to savings in acid consumption and in fertilizer manufacturing plant capacity for calcareous soils.     

重钙造粒中和剂的选择与磷退化的研究

重过磷酸钙产品在出厂销售前应将过高的游离酸用中和剂中和。研究结果指出,钙镁磷肥和石灰石粉均可使用,尤以后者为好。粉状重钙造粒时使用中和剂后,产品的Ｐ２Ｏ５会有少量的退化现象,在实际操作中应引起注意。     

重钙及普钙中有效磷的直接提取

本文研究了用中性柠檬酸铵直接提取重钙及普钙中的有效磷 ,较之现行化工行业标准规定的方法减少用时 2h以上 ,分析结果与标准法结果的绝对差值小于 0 .1 0 %。     

重钙添加剂的研究和应用

针对某些国产磷矿在浓酸法重钙生产中物料物理性质较差的现象，通过试验，筛选 出了适合于浓酸法重钙生产的添加剂。结果表明：浓酸法重钙生产中使用添加剂能够改善重钙物料的物理性质、尤其对于反应活性较低的磷矿效果为显著，为利用国产反应活性较低的磷矿制取重钙提供了一条途径。该添加剂已应用于湖北、贵州、云南等地的重钱生产厂，效果良好。     

Factors affecting the agronomic effectiveness of phosphate rock for direct application

Phosphorus (P) is critically needed to improve soil fertility for sustainable crop production in large areas of developing countries. In recent years, phosphate rock (PR) for direct application has been tested in tropical acid soils as a potential alternative to conventional water-soluble P fertilizers like single superphosphate (SSP) and triple superphosphate (TSP). Some developing countries have PR deposits which, if used to supplement other imported P fertilizers, would allow a saving of much needed foreign exchange. Solubility of P fertilizers is not the only criterion in selection of the most suitable P fertilizer. This paper discusses the results of experiments to compare the relative agronomic effectiveness (RAE) of various PR sources with respect to SSP or TSP as influenced by four important factors: PR sources, soil properties, management practices, and crop species. Under certain conditions, PRs can be agronomically effective.