Mining and Beneficiation of Phosphate Ore

Abstract

The first commercial production of phosphate rock began in England in 1847. A wide variety of techniques and equipment is used to mine and process phosphate rocks in order to beneficiate low-grade ores and remove impurities. The eighth chapter of this book deals with mining and beneficiation of phosphate ore. The principle and operating conditions of important parts of manufacturing process including separation, classification, removing of carbonates, calcination and flotation was described. The chapter ends with description of techniques used for extraction of rare earth element. phosphates are very similar. The separation by physical means becomes even impossible when the carbonate minerals are finely disseminated into the phosphate particles. KeywordsAn alternative technique for the beneficiation of these ores is the calcination. Calcination is the process of heating the ore to a high temperature ranging from 800 to 1000°C to decompose CaCO 3 and MgCO 3 to CaO, MgO and gaseous CO 2 . The CaO and MgO formed are then removed as hydroxides by quenching the calcined product in water and washing. The most common chemical reagent used to enhance the removal of calcium and magnesium hydroxides is ammonium chloride.Chemical dissolution of carbonate minerals (calcite and dolomite) from calcareous phosphate ores, without the calcination, using organic acids also proved to be capable of beneficiating the calcareous phosphate ores on the laboratory scale.4. Phosphate ores associated with organic matter (black or brown phosphates): ores of this type are generally beneficiated by heating the ore up to about 800°C. This type of calcination burns organic material and residual organic carbon without significantly affecting the superior qualities of sedimentary phosphates such as the solubility and reactivity.Furthermore, as a result of low calcination temperature, the reduction of calcium sulfate, present in ore, to corrosive calcium sulfide by the organic matter is minimized. During the burning of organic matter, the following two conditions must be kept: organic carbon must be decreased to less than 0.3% to minimize the gassing in the wet phosphoric acid processing, and apatite CO 2 must be maintained at a level close to 2% to allow good reactivity of calcined product.5. Phosphate ores containing more than one type of gangue minerals: many sedimentary phosphate deposits contain mixtures of undesired constituents. These ores require a series of beneficiating operations during their processing depending on the type of gangue minerals present in each ore. This may include, after the size reduction, the combination of attrition scrubbing, desliming, flotation, gravity separation and/or calcination. Each flow sheet is to be designed after thorough characterization and testing of a representative sample of the exploited ore.Igneous and metamorphic phosphate ores: the main gangue materials in these ores are sulfides, magnetite, carbonates (calcite, dolomite, siderite and ankerite), nepheline syenite, pyroxenite, foskorite,...

Utilization of Apatite Ores

“…Another applications of phosphoric acid include the treatment of surface of metals (Section 10.8), the utilization in dentistry [28], [29], [30], [31], [37], [38] (described in Section 10.1.2), phosphate binders [32], geopolymers [33], phosphoric acid fuel cells [34], [35], [36], gel-based electrolytes [39] and solid membranes [40], [41], [42] for fuel cells, the activation of carbon adsorbents [43], [44] and catalysts [45], [46], the modification of zeolites [47], catalytic decomposition of H 2 O 2 [48] and organic syntheses, e.g. esterification [49], [50].…”

“…There are two processes ( Fig. 9) described below used for the preparation of phosphoric acid [7], [26], [53], [54], [56], [57]:…”

“…As more and more phosphorus has been added to the ecosystem, many lakes and coasts have seen an increased algae growth, which in some cases have led to serious eutrophication and dead zones due to lack of oxygen [91]. CARPENTER and BENNETT [115] even consider that the planetary limits for the eutrophication of freshwater due to phosphorus have already been exceeded. It is possible to recycle phosphorus from different sources (human excreta, manure, different types of waste products, etc.)…”

Recovery of uranium from phosphate ore in the Sheikh Habil-Iran mine: part I— multivariable optimization of leaching process using the response surface method

“…Sedimentary phosphate ores with a low phosphate grade (less than 30%) require some pre-treatment to remove tailings before producing phosphoric acid. The type of pre-treatment depends on ore properties such as density, particle size, morphology, surface chemistry, magnetic properties, electrical conductivity, color, and porosity of particles ( Ptacek, 2016 ). Today, most (more than 75%) phosphate ores are processed using the wet-phosphoric acid (WPA) process, with sulfuric acid as the digestive acid.…”