复混肥几种配料体系中的成盐反应研究

文章从物理化学的角度出发研究了几种复混肥配料体系在复混肥生产过程中混合物料间的化学反应。重点研究了分别用氨、碳酸氢氨、石灰粉、钙镁磷肥等对过磷酸钙(或重过磷酸钙)进行改性处理的过程中发生的化学反应以及这些反应对混合物料的物理化学性质的影响,研究发现这些中和剂在进行普钙(或重钙)的改性处理时各有优劣,应根据生产的实际情况慎重选择;尿素的缩合反应;尿素的水解反应及其影响;有硝铵存在的复混肥配料体系中混合物料间的放热反应;钾盐、复盐的置换反应及其对混合物料物化性质的影响。     

复混肥加工中化学反应的运用

阐述复混肥生产过程中如何恰当利用原料间的各种化学反应。例如提高物料黏性有利造粒;加入某些物质消除反应产生的液相;利用化学反应热蒸发水分减轻干燥负荷等等,以达到消除生产中的不利因素,提高产量、质量,降低消耗的目的。     

蒸汽团粒法复混肥生产中粉尘污染问题及对策探讨

粉尘污染是复混肥生产中普遍存在的问题,分析了蒸汽团粒法复混肥生产中产生粉尘的主要因素,分别是混合后的造粒物料可塑性差或配料不均衡、蒸汽量与造粒物料量的比例不适中、造粒工况和干燥温度控制不当,以及防尘除尘措施不到位,并针对这些因素提出了对策。     

关于中和处理过磷酸钙的计算

关于中和处理过磷酸钙的计算曾曼华（湖北省仙桃市磷肥厂）尿素——过磷酸钙系复混肥料是以尿素和过磷酸钙为基础的粒状肥料。由于过磷酸钙中有游离酸和磷酸一钙，尿素与其混合后发生的主要反应有：Ｈ＿３ＰＯ＿４＋ＣＯ（ＮＨ＿２）＿２＝ＣＯ（ＮＨ＿２）＿２·Ｈ＿３Ｐ...     

混复肥生产过程中的普钙氨化

一、普钙氨化的重要性在以普钙—尿素为基质体系的混复肥生产过程中,普钙改性——氨化是极为重要的工序,普钙氨化不好,甚至影响混复物料不能完成造粒过程;若氨化完善,则造粒顺利,而且可得到不胶结、不松散、不吸湿、不含游离酸的商品性混复肥。普钙不改性,直接与尿素混合,就不可能成粒。这是因为普钙与尿素发生下列反应:     

过磷酸钙预处理对复混肥生产的影响

过磷酸钙预处理对复混肥生产的影响刘运成（湖北天门化工总厂复混肥分厂）干法工艺生产氮磷钾粒状复混肥料的主要原料是尿素、氯化铵、氯化钾、硫酸铵、硝酸铵、过磷酸钙等。各种原料经过破碎、混合、加水造粒，然后干燥、过筛，尺寸过大的颗粒经破碎后再循环过筛，过小的...     

复混肥造粒用海泡石与磁土作为调理剂

复混肥造粒用海泡石与磁土作为调理剂谭丽光欧阳海涛（株洲市湘江氮肥厂４１２００５）中图分类号ＴＱ４４４本文将对团粒法生产尿素、过磷酸钙系列复混肥过程中易出现的几个主要问题进行讨论,以寻求解决的途径。１复混肥生产中易出现的问题对尿素、过磷酸钙系列复混肥,...     

复混肥生产中的原料预处理方法

复混肥料生产常用的基础原料有过磷酸钙、尿素、钙镁磷肥、硫铵、硝铵、硫酸钾、氯化钾等,其中,过磷酸钙和尿素是用的最多,用量最大的复混肥生产原料。目前,国内生产的过磷酸钙(简称普钙)一般含游离水10—18%,游离酸5～10%。这种普钙不适于生产中的破碎和造粒,因此,必须对原料普钙进行予处理,处理方法如下:     

我厂复混肥生产中产生结疤的原因及解决措施

以尿素、磷铵、过磷酸钙、硫酸钾等原料用团粒法生产复混肥的过程中，烘干机、斗提机、卧式双辊链条粉碎机常产生结疤，分析产生结疤的原因是物料含水分和游离酸过高所致，并提出相应解决措施。     

尿素-过磷酸钙系混合肥料的生产(二)

生产尿素-过磷酸钙粒状混合肥料物理化学问题已在本文第一部份作了介绍。粒肥的生产过程比粉肥的生产过程繁复,因为它比粉状混肥生产增加了配料的成粒、干燥、筛分和冷却等操作。就整个生产过程来说,它和其它氮肥为配料的粒肥生产过程大致相仿。但是,操作条件有较大差异。操作条件控制的允许波动范围也比其它配料的粒肥生产苛刻得多。根据试验,我们将尿素-过磷酸钙系粒状混合肥料生产过程的主要工艺条件、产品的物理性质和工艺过程等问题作简单介绍。     

预中和-单管二次氨化技术生产DAP/NPK复合肥工艺

分析常压两步中和喷浆造粒工艺、预中和-转鼓氨化工艺、管式反应器工艺生产DAP/NPK的弱点,介绍为克服这些弱点而研究开发的预中和-单管二次氨化技术的主要工艺过程及该工艺的技术特点和比较优势.提供了贵溪化肥厂的试生产及其效益情况,若月产NPK产品2.5万吨,每月可增加经济效益140万元.     

高塔熔体复合肥造粒工艺成品颗粒空壳现象分析和探讨

在高塔熔体复合肥造粒工艺中,造成颗粒出现空壳现象的原因主要包括熔融物料含水量、化学反应、制浆工艺及造粒喷头等。根据出现空壳的原因,给出了解决问题的措施。     

Quantum Calculations of VX Ammonolysis and Hydrolysis Pathways via Hydrated Lithium Nitride

Recently, lithium nitride (Li₃N) has been proposed as a chemical warfare agent (CWA) neutralization reagent for its ability to produce nucleophilic ammonia molecules and hydroxide ions in aqueous solution. Quantum chemical calculations can provide insight into the Li₃N neutralization process that has been studied experimentally. Here, we calculate reaction-free energies associated with the Li₃N-based neutralization of the CWA VX using quantum chemical density functional theory and ab initio methods. We find that alkaline hydrolysis is more favorable to either ammonolysis or neutral hydrolysis for initial P-S and P-O bond cleavages. Reaction-free energies of subsequent reactions are calculated to determine the full reaction pathway. Notably, products predicted from favorable reactions have been identified in previous experiments.     

Agronomic and environmental aspects of phosphate fertilizers varying in source and solubility: an update review

This review discusses and summarizes the latest reports regarding the agronomic utilization and potential environmental effects of different types of phosphate (P) fertilizers that vary in solubility. The agronomic effectiveness of P fertilizer can be influenced by the following factors: (1) water and citrate solubility; (2) chemical composition of solid water-soluble P (WSP) fertilizers; (3) fluid and solid forms of WSP fertilizers; and (4) chemical reactions of P fertilizers in soils. Non-conventional P fertilizers are compared with WSP fertilizers in terms of P use efficiency in crop production. Non-conventional P fertilizers include directly applied phosphate rock (PR), partially acidulated PR (PAPR), and compacted mixtures of PR and WSP. The potential impacts of the use of P fertilizers from both conventional (fully acidulated) and non-conventional sources are discussed in terms of (1) contamination of soils and plants with toxic heavy metals, such as cadmium (Cd), and (2) the contribution of P runoff to eutrophication. Best practices of integrated nutrient management should be implemented when applying P fertilizers to different cropping systems. The ideal management system will use appropriate sources, application rates, timing, and placement in consideration of soil properties. The goal of P fertilizer use should be to optimize crop production without causing environmental problems.     

Heavy metal contaminants in inorganic and organic fertilizers

Commercial phosphate (P) fertilizers contain small amounts of heavy-metal contaminants which were minor constituents in phosphate rock (PR). Animal manures and sewage sludges (biosolids) are the main organic fertilizers and the latter also may contain heavy-metal contaminants. Heavy metals in biosolids may be found in the inorganic form or may be organically complexed, which could affect their chemical reactions in soil. These heavy metals may accumulate in soil with repeated fertilizer applications. Cadmium (Cd) is the heavy metal of most concern because it may affect human health. Other heavy metals of possible significance are arsenic (As), chromium (Cr), lead (Pb), mercury (Hg), nickel (Ni), and vanadium (V). Some countries have set tolerance limits on heavy-metal additions to soil because their long-term effects are unknown. These limits usually are set for the tillage layer (surface 20–30 cm) of soil where most root activity occurs. Controls on heavy-metal concentrations in sewage biosolids and their maximum total and annual loading rates to soil have been imposed in some countries. Regulations also have been proposed for phased-in limits on maximum heavy metal concentrations permitted in P fertilizers, or they are already in effect. Most of the fertilizer regulations relate Cd limits to P concentrations, so P application rates dictate Cd inputs to soil. Regulations affecting sewage biosolids include a number of heavy metals, while those concerning P fertilizers only include limits on Cd at this time.     

有机农业不应排斥化肥

阐述了有机农业、绿色农业不应排斥化肥的原因。合理施用化肥不仅可使农产品增产、改善品质,我国政府也大力倡导科学施肥,而且化肥支撑了增长人口的生存。如要继续科学高效地使用耕地,化肥仍将是重要物资;有机肥取代化肥尚待时日,难点较多;即使进入循环经济、未来社会,仍将会增加对肥料的需求,因此应尽快纠正有机农业等排斥化肥的状况。     

Solid-State Chemistry of Cyanine-Type Dyes and the Effect of Two Novel Counterions on Their Crystal Properties

Organic dyes undergo a variety of solid-state chemical processes, including intra- and intermolecular reactions, gas-solid reactions, and polymorphic transformations. The properties of dye solids are markedly affected by this chemistry. This paper reviews solid state dye chemistry from the literature and reports in detail the chemistry of two novel cyanine dye salts whose properties are controlled by the nature of their counterions. In cyanine-oxonol salts, the oxonol counterion is a large planar dye which forms crystalline dye aggregates with cyanine ions. There is a multiplicity of polymorphic forms of these mixed dyes reflecting multiple favorable dye aggregate geometries. The cyanine-borate salts undergo intermolecular solid-state reactions. In either large single crystals or dispersions of the latter salts in polymer binders, alkyl transfer from the anion to the chromophore can be induced thermally or photochemically.     

离子液体的合成与应用

离子液体即在常温及附近温度下为液体的离子物质,已合成的主子液体已达上百种,离子液体的合成方法有复分解法和中和法,其应用研究领域有分离过程,化学反应特别是催化反应以及电化学等方面。     

The dissolution of North Carolina phosphate rock in some south-western Australian soils

To investigate the prospects for phosphate rock (PR) application in south-western Australia (WA), 228 soil samples were collected from the main agricultural areas and their chemical and textural properties analyzed. All the samples were incubated with North Carolina PR and the amount of PR dissolved was measured using the Ca technique. The amounts of PR dissolved were generally low and only 29 of the soils dissolved more than 40% of the added PR. These are located in the wettest area of WA, to the west of the 800mm isohyet. Within this area a variety of soil types were able to dissolve PR including vertisols, spodosols, alfisols and ultisols. Of these the humic podzols and peaty sands appeared to have the best potential for PR application. It is also from some of these soil types that much P from water-soluble fertilizers is leached so that the slow release characteristics of PR fertilizers may be beneficial.