磷矿反应活性和抗阻缓性研究

研究了云南昆阳和贵州开阳两种磷矿的反应活性和抗阻缓性,SPSS数学软件回归分析结果表明:磷矿分解率与混酸中硫酸的质量分数之间有良好的线性关系,昆阳磷矿抗阻缓系数为7.104,开阳磷矿抗阻缓系数为7.001,昆阳磷矿的反应活性较开阳磷矿高.     

磷矿浮选尾矿矿石特性研究

以贵州瓮福磷矿浮选后的尾矿资源为研究对象,研究了其反应活性、抗阻缓性及酸解反应工艺特性.得出,尾矿主要物相是白云石,其反应活性为99.65%,抗阻缓系数为12.87,最佳酸解反应工艺条件为:反应时间90 min,液固比3,浸出温度80℃,酸过量系数1.05,MgO的浸出率高于P2O5的浸出率(均高于95%).研究表明:瓮福磷矿浮选尾矿反应活性好,有一定的抗阻缓性,MgO和P2O5在酸解过程中近乎是同时浸出,只是前者略高于后者.本研究可为综合利用浮选尾矿中的镁、磷提供必要的基础理论依据,对低品位磷矿的利用有一定借鉴作用.     

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用浓酸固化法。     

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。     

磷矿的风化反应与酸解活性的关系

通过对磷矿风化水解反应的分析，说明风化反应与磷矿的化学组成及微观结构有着密切的联系。磷矿中碳酸盐的含量及在磷矿晶体中的存在状况对磷矿的酸解反应活性有着较大的影响。由磷矿酸解反应活性与磷矿晶体微观结构的关系，指出易风化的磷矿具有较好的酸解反应活性。     

胶磷矿酸解反应活性的研究

研究用硫、磷混酸分解贵州福泉和开阳磷矿、四川清平和金河磷矿的反应速度，并比较这几种磷矿被酸分解的活性。研究结果表明，福泉磷矿被酸分解的活性最强，清平磷矿活性最差。此外，还探讨了磷矿的显微结构、比表面积及组成等对其酸解反应活性的影响。     

磷块岩的分形特征和反应活性

采用电子扫描显微镜和图像分析仪研究了我国三种典型的磷矿颗粒的表面结构,并提出了分形模型。由于沉积性磷块岩存在着自相似性,所得到分数维值可进一步预测磷矿颗粒内的磷灰石团粒分布率。同时对反应活性与表现分形间的关系也进行了探讨。     

硫酸脲分解磷矿反应动力学

通过硫酸脲分解磷矿的搅拌强度和磷矿粒度实验,探讨其中的传递过程。实验研究表明,硫酸脲分解磷矿为典型的缩芯反应,反应过程受产物形成的固膜扩散所控制,在排除液相扩散和反应粒子表面及微孔影响下,进行反应动力学实验。建立了硫酸脲与磷矿反应的动力学模型,由实验数据求得动力学参数,其反应活化能为12．73kJ／mol。     

Properties of unreacted rock residues in partially acidulated phosphate rocks affecting their reactivity

The nonacidulated P fraction of partially acidulated phosphate rocks (PAPR) was obtained by extraction with alkaline ammonium citrate solution. Investigations on this unacidulated rock residues using standard analytical techniques and electronbeam microanalysis showed a surface coating with highly increased fluorine content surrounding the unreacted phosphate rock particles. The coating may be responsible for low reactivity of the residues and their inferior agronomic effectiveness as compared to the original mother rock phosphate. Furthermore, the existence of dicalciumphosphate and Fe—Al—P compounds in PAPR products make solubility tests based on alkaline ammonium citrate appropriate to gauge the acidulated and easily plant available P fraction. Only after the removal of these compounds with citrate solution is an assessment of the potential agronomic value of the nonacidulated rock residues in 2% formic acid possible.     

Agronomic evaluation of modified phosphate rock products

Phosphorus (P) is critically needed to improve the soil fertility for crop production in large areas of developing countries. The high cost of conventional, water-soluble P fertilizers constrains their use by resource-poor farmers. Finely ground phosphate rock (PR) has been tested and used as a direct application fertilizer on tropical acid soils as a low-cost alternative where indigenous deposits of PR are located. However, direct application of PR with low reactivity or with inappropriate soil/crop combinations does not always give satisfactory results. Partial acidulation of PR (PAPR) or compaction with triple superphosphate (PR + TSP) or single superphosphate (PR + SSP) represent technologies that can be used to produce highly effective P fertilizers from those indigenous deposits. Numerous field trials conducted by IFDC in Asia, sub-Saharan Africa, and Latin America have demonstrated that PAPR at 40-50% acidulation with H₂SO₄ or at 20% with H₃PO₄ approaches the effectiveness of SSP or TSP in certain tropical soils and crops. This paper discusses how the agronomic effectiveness of PAPR is affected by mineralogical composition and reactivity of PR used and by soil properties and soil reactions. The paper also indicates that if a PR has high Fe₂O₃ + Al₂O₃ content, it may not be suitable for PAPR processing because of the reversion of water-soluble P to water-insoluble P during the PAPR manufacturing process. Under these conditions, compaction of PR with water-soluble P fertilizers (e.g. SSP, TSP) at P ratio of approximately 50:50 can be agronomically and economically attractive for utilizing the indigenous PRs in developing countries.     

Agronomic evaluation of fertilizer products derived from Sukulu Hills phosphate rock

Partial acidulation of phosphate rock (PR) or compaction of PR with soluble P fertilizers can improve the usefulness of unreactive PR for use as P fertilizer. A greenhouse study was conducted to evaluate nonconventional phosphate fertilizers derived from a low reactive Sukulu Hills PR from Uganda. Raw PR (which contained 341.0 g kg^–1 Fe₂O₃), beneficiated or concentrate PR, partially acidulated PR (PAPR) and PR compacted with triple superphosphate (TSP) were evaluated. Compacted materials had a P ratio of PR:TSP = 50:50. PAPR materials were made by 50% acidulation with H₂SO₄. TSP was used as a reference fertilizer. Fertilizers were applied to an acidic (pH = 5.4) Hiwassee loam (clayey, kaolinitic, thermic Rhodic Kanhapludults) at rates of 0, 50, 100, 200, 300 and 400 mg P kg^–1 soil. Two successive corn (Zea mays L.) crops were grown for 6 weeks. Compacted concentrate PR + TSP and raw PR + TSP were 94.4 and 89.7% as effective as TSP, respectively, in increasing dry-matter yields for the first corn crop. PAPR from the concentrate was 54.8% as effective as TSP. Raw PR, concentrate PR and the PAPR from the raw PR were ineffective in increasing dry-matter yields. The same trends were obtained when P uptake was used to compare effectiveness. Ineffectiveness of the raw PR and its corresponding PAPR was attributed to a high Fe₂O₃ content in the raw PR. Bray I and Pi paper were found to be nearly equally suitable at estimating available P in the soils treated with responsive fertilizer materials. Mehlich 1 overestimated available P in soil treated with raw PR, concentrate PR or the PAPR from the raw PR.     

我国磷矿资源贫化趋势与对策探讨

介绍我国主要磷矿区资源贫化趋势,对原因进行了分析。并针对低品位磷矿及伴生资源进行综合利用,提出了一些技术与政策思路。     

利用磷矿制备饲料添加剂磷酸二氢钙

以磷矿为原料制备磷酸,通过化学沉淀法脱氟除杂质得到净化的磷酸,再将净化后的磷酸与碳酸钙反应制备饲料级磷酸二氢钙.考察了硫酸质量分数、石灰乳用量、反应时间和反应温度4个因素对磷酸二氢钙产率的影响,得到了制备磷酸二氢钙的最佳工艺条件:硫酸质量分数60％,石灰乳用量7.00 g,反应时间1.5h,反应温度50℃.在此最佳工艺...     

Influence of phosphate rock reactivity and granule size on the effectiveness of ‘biosuper’

A pot trial was conducted to determine the influence of phosphate rock (PR) reactivity and granule size on the effectiveness of biosuper. Perennial ryegrass was grown as the test crop for 9 months in a volcanic ash soil of pH 5.4. The PRs used were North Carolina (NC) (reactive) and Florida (Fl) (less reactive). Single superphosphate was used as the standard fertilizer. The fertilizers were added at 6 rates 3 mm below the soil surface.The dry matter yield and phosphate uptake data indicated that the effectiveness of the fertilizers were in the order of NC/S (biosuper indicated by adding S to the PR names) = superphosphate > NC > F1/S > F1 > control. The performance of biosupers and PRs relative to superphosphate, improved with time. The effectiveness of NC/S increased by 18–30% and that of F1/S by 50–70%, depending on the rate of application, in comparison with addition as PR granules. Plant phosphate uptake and soil Olsen bicarbonate extractable phosphate values indicated that the increase in yield in biosuper treatments was due to enhanced phosphate supply, caused by the oxidation of sulphur to sulphuric acid and the subsequent reaction of the acid with the PRs.Increasing the NC/S granule size from 0.2–0.5 to 1–2 mm range resulted in a small but significant decrease in effectiveness. However, the calculated yield maxima were the same. The size of the granules did not make significant difference with F1/S.Olsen bicarbonate extractable phosphate values increased by 140 to 310% and 140 to 330% respectively when NC and Fl were added as biosupers compared to addition as PR granules. The values for superphosphate decreased rapidly with time and were less than those for biosupers five months after addition of the fertilizers.     

The effects of nitrogen fertilizer form on the plant availability of phosphate from soil,phosphate rock and mono-calcium phosphate

A glasshouse trial using lettuce as the test crop, and laboratory incubations were used to evaluate the influence of various nitrogen fertilizers on the availability of phosphate from an unfertilized loamy sand soil and from the same soil fertilized with Sechura phosphate rock or monocalcium phosphate. The order in which nitrogen fertilizer form increased plant yield and P uptake from soil alone and from soil fertilized with the rock was ammonium sulphate > sulphurised urea > ammonium nitrate > urea > potassium nitrate. For each rock application (both 30 and 60 mg/pot) and for soil alone, increased P uptake by the plant correlated well with decreased soil pH. In soil fertilized with the soluble P form, monocalcium phosphate, the form of the nitrogen fertilizer had little effect on plant P uptake. Subsequent laboratory incubation studies showed that increased dissolution of soil-P or Sechura phosphate rock did not occur until acidity, generated by nitrification or sulphur oxidation of the fertilizer materials, had lowered soil pH to below 5.5. A sequential phosphate fractionation procedure was used to show that in soils treated with the acidifying nitrogen fertilizers, ammonium sulphate and urea, there was considerable release of Sechura phosphate rock P to the soil, amounting to 42% and 27% of the original rock P added, respectively.     

中国磷矿资源和磷肥生产与消费

介绍了中国磷矿资源特点、磷矿开采状况以及磷肥生产、消费情况,并就目前磷矿开采中存在的问题进行了讨论,对中国磷肥工业的持续发展提出了相应的对策和建议.     

A test for phosphate rock reactivity in which solubility and size are combined in a dissolution rate function

A test for phosphate rock (PR) reactivity has been developed based on a representation of certain fundamental properties of the rocks designated the Dissolution Rate Function. The function and properties have been shown to be those important in models of the dissolution rate of PRs in soil. The properties are size or mass distribution with size, solubility product, P content and particle density. In practice the solubility product is measured in terms of the P concentration attained in a standard solution, simulating that in an average soil with respect to pH, Ca and ionic strength.The test compares favourably with those using citric and formic acids, using published results for the relative agronomic effectiveness of 11 PRs, both unground and ground. The agronomic data also indicated that particle sizes < 0.15 mm can be regarded as equivalent to the size range of 0.10 to 0.15 mm.     

世界磷矿生产消费格局及其变化

介绍世界磷矿资源分布、生产消费格局及其变化。世界磷矿资源分布比较集中,其中以摩洛哥储量最多;世界磷矿石主要用于磷肥生产,其消费量呈增长趋势,其中美国磷矿石消费量下降、中国磷矿石消费量增长,磷矿石价格波动下降;世界磷酸盐产能、产量均增长,磷肥供应持续过剩,预测磷肥供应格局将向中东、北非地区转移。