China
Africa
Explore chapters and articles related to this topic
Petroleum Geochemical Survey
Published in Muhammad Abdul Quddus, Petroleum Science and Technology, 2021
Phosphate mineral is a salt of phosphoric acid {H3(PO4)}. Phosphate ion (PO4)3– is an isolated tetrahedral coordinated radical. The radical combines with h equivalent positive cations, so that a neutral and stable phosphate mineral is produced. Variable physical properties are witnessed in the phosphate minerals. The mineral is vitreous, dull, with moderate density and average hardness. The phosphorus element in the ion is replaceable by arsenic, vanadium and antimony atoms to produce arsenate (AsO4)3–, vanadate (VO4)3– and antimonite (SbO4)3– minerals. About 200 phosphate minerals are known, often associated with other minerals; halite (Cl, Br and F)–1 and hydroxide (OH)– minerals. Some examples of phosphate minerals are as follows: Amblygonite (lithium, sodium, aluminum fluoride, hydroxide, phosphate).Anapaite (hydrated iron, calcium phosphate).Apatite (calcium chloride, fluoride, hydroxide, phosphate). Chloro-apatite (calcium chloro-phosphate) occurs in soil. It is a source of phosphorus food, consumed by plants. The fluoro-apatite (calcium fluoro-phosphate) mineral is found in animal bone. So the mineral is called ‘biological apatite’.
Crop Improvement and Applied Nanobiotechnology
Published in Cherry Bhargava, Amit Sachdeva, Nanotechnology, 2020
Apatite (e.g., Ca10(PO4)6(OH)2), a rock phosphate, is one major source of phosphorous, a macronutrient for plant growth. Abandoned lands have comparatively high pH, which prevents the dissolution of phosphorous in the soil and the addition of zeolite to apatite with the aim to create a sink for Ca2+ maintaining the pH, and leading to bioavaibility of phosphorous to the plants (Liu, 2011; Knox et al., 2003).
Rock Forming Minerals
Published in Aurèle Parriaux, Geology, 2018
This mineral has a vitreous luster. It is faintly colored in tones of yellow-green or pink-purple. Its hardness is 5 on the Mohs scale; its density is 3.2 · 103 kg/m3. Its principal cleavage is poorly developed. Apatite is the most important ore of phosphorus; it is widely disseminated in all types of rocks, as an accessory mineral and in oxidation zones of some sulfide deposits.
Rare earths of the Murmansk Region, NW Russia: minerals, extraction technologies and value
Published in Applied Earth Science, 2023
Andrey O. Kalashnikov, Nataly G. Konopleva, Konstantin P. Danilin
Apatite and titanite. Apatite group minerals are the main source of phosphorus for fertiliser production. Also, apatite contains REE and Sr as potential economic components. Titanite is a Ti raw material and also contains REE (Table 2). The process of successful industrial extraction of REE from apatite Khibiny ores was already carried out in Finland in the 70s and 80s. Ore exported from the deposits of the Kola Peninsula underwent industrial purification using ion-exchange reactions. But the low prices for REE at that time led to this process becoming economically unprofitable (Sarapää et al. 2013). At the moment, sulphuric acid is used at the JSC Phosagro, the main enterprise that processes apatite ore. Even with the sulphuric acid treatment process, technologies are being developed that allow the extraction of REE if a lower concentration of H2SO4 is used (Ogata et al. 2016). However, H2SO4 carries great risks to the environment and human health due to industrial waste (release of SO2 into the air and water) (Folinsbee 1993) but now this process is already used by JSC Phosagro without REE extraction, so it can be implemented without increasing of environmental risks. Technology for extracting REE during nitric acid processing of apatite ore also exists and does not require large capital expenditures, it makes it possible to extract REE from apatite ore (Lokshin and Tareeva 2008; Lokshin et al. 2016; Osmak et al. 2016). This technology is used at the enterprises of JSC Acron. REE are partially extracted.
Development of nitrogen-doped hydroxyapatite ceramics
Published in Journal of Asian Ceramic Societies, 2020
Nao Kaneko, Yuhei Suzuki, Ryo Umeda, Ryota Namiki, Chihiro Izawa, Tomoko Ikeda Fukazawa, Michiyo Honda, Takahiro Takei, Tomoaki Watanabe, Mamoru Aizawa
Hydroxyapatite (Ca10(PO4)6(OH)2; HAp) is widely used as a biomaterial in clinical applications due to its high biocompatibility and osteoconductivity. However, stoichiometric HAp is inferior with respect to bone formation in auto-grafting. As one of the methods to enhance the osteoconductivity of HAp, its chemical composition should be altered to achieve a molecular composition similar to biological apatite. It is also well-known that the HAp lattice can easily substitute cationic and anionic ions. Biological apatite in bone and teeth is substituted with various ions in the crystal structure. Thus, HAp crystals have much strain and many defects, and thus have more efficient bioactivity than pure HAp ceramics [1,2]. In previous reports, various ions, such as Si [3], Sr [4], Zn [5], Cu [6], Mg [7], and B [8], in bone mineral were substituted into the HAp structure.
Bioactive coating as a surface modification technique for biocompatible metallic implants: a review
Published in Journal of Asian Ceramic Societies, 2019
B. Priyadarshini, M. Rama, U. Vijayalakshmi
Hydroxyapatite [Ca10 (PO4)6 (OH)2] is an important calcium phosphate-based material that has been used in biomedical applications due to their better biocompatibility with the physiological system stemming from its negligible toxicity and inflammation causation. Its poor mechanical properties limit its use as a bone substitute, however, to replace damaged or diseased bone in various applications [32,33]. Hence, it can be used as a coating material for improving and giving an edge to the mechanical properties of stainless steel or titanium alloys to promote bone ingrowth as well as a filling material for correcting amputated bone. Upon implantation, this bioactive material easily achieves an apparent ability to attach to the implant-tissue interface with good osteoconductive behavior by the formation of an apatite layer. According to the need, HAP has been modified to form dense-compact HAP and porous HAP for various biomedical applications. Augmenting HAP with a polymer matrix tends to improve its mechanical strength and bone-bonding ability [32,34] HAP can also be prepared from different waste materials such as egg and snail shells, and the products have been found to exhibit excellent biocompatibility with various osteoblast and fibroblast cell lines [35].