Beneficiation of Low-Grade Phosphate Deposits by a Combination of Calcination and Shaking Tables: Southwest Iran
Three quarters of the world’s phosphate deposits are of sedimentary origin and 75%–80% of those include carbonate gangue. In this study, carbonate sedimentary phosphate deposits of the Lar Mountains of southwest Iran are studied. These deposits consist mainly of calcite, fluorapatite, quartz, kaolinite and illite, with an average P2O5 grade of 9%–10% (low-grade). Various pre-processing and processing methods have been developed for concentrating low-grade phosphate up to marketable grade and this study aims to select the optimal method to produce an economically viable grade of phosphate concentrate from low-grade ore. Different concentration methods, including calcination and gravity separation, were applied on samples at both a laboratory and semi-industrial scale (pilot scale). Using an integrated method of calcination (performed in a rotary kiln) and shaking table for concentrating the low-grade phosphate ore, the results show promise at producing grades of 30.77% P2O5 with 60.7%–63.2% recovery.
Caractérisation granulo-chimique et minéralogique du minerai de phosphate de Bled El Hadba.
Tébessa has the largest phosphate deposit in Algeria. It is estimated at 2 billion tons by the mining company of phosphates. Phosphates are of great importance regarding their applications in several sectors including the fertilizer industry and phosphoric acid. However, this sector imposes quality requirements to their concentrated phosphates, which impose to eliminate the annoying and harmful impurities such as trace elements (Pb, Cd, U, Hg, As and others) considered toxic if they exceed the normal threshold, either to humans or to the environment. We are interested in this study on the petrographic, mineralogical and chemical characterization of the three layers of the deposit of Bled El Hadba, its objective is the qualitative and quantitative study of major and trace elements. The completion of this study required the use of several methods of analyses XRD, MEB, IR and ICP prior, to define the stitches of the release of phosphoric elements and gangue minerals present in the raw material, the chemical composition in major part, as well as their distribution by size fractions. The study of trace performed by mass spectrometry and inductively coupled plasma with the ICP-MS torch type plasma has identified certain items, mainly consisting of rare earth and transition metals. The results have shown significant differences both for different layers. The study also showed a close relationship between the trace elements and the different mineral species (apatite, silicate and dolomite), through substitution operations.
Morphological characterization of Eustrongylides sp. larvae (Nematoda, Dioctophymatoidea) parasite of Rhinella marina (Amphibia: Bufonidae) from Eastern Amazonia.
Absctract Eustrongylides spp. nematodes have birds as final hosts and uses other vertebrates as intermediate/paratenic host (fish, amphibians and reptiles) and have zoonotic potential. In amphibians, the larvae may be located in the subcutaneous tissues, liver and mesentery, between the muscle fibres, especially in the lower limbs. Rhinella marina, which is widely observed in Brazil, has exhibited complex diversity in its helminth fauna, reflecting the unique habitat of the Amazon biome. For the first time, this study describes the morphological aspects of third-stage larvae of Eustrongylides sp. in Rhinella marina from Santa Cruz do Ararí, Marajó Archipelago, Eastern Amazonia, using light and scanning electron microscopy.