As presents in water in different oxidation states, most commonly as arsenic As III (arsenite) and As V (arsenate) form. The predominant As III species are …
Semantic Scholar extracted view of "Arsenite and arsenate binding to ferrihydrite organo-mineral coprecipitate: Implications for arsenic mobility and fate in natural environments." ... (II) in soils, sediments, and aquatic systems is strongly dependent on adsorption behaviors occurring at the mineral-water interface, and this process may …
The arsenate minerals, which are salts of arsenic acid, contain arsenate groups (AsO 4) in which four oxygen (O) atoms are arranged at the corners of a tetrahedron about a central arsenic (As) atom.Each arsenate tetrahedron has a net electric charge of -3, which is neutralized by large, positively charged metal ions (e.g., calcium, manganese, or ferrous …
Arsenic occurs in many minerals, usually in combination with sulfur and metals, ... a process of treating wood with chromated copper arsenate (also known as CCA or Tanalith) ... Arsenate (+5 oxidation state) is the …
Arsenic minerals are mainly arsenopyrite, realgar, and orpiment, in some oxidation zones of sulfide deposits is arsenate mineral. China has the world's unique realgar (As 4 S 4 ) resources, widely distributed in Hunan, Guizhou, Sichuan, Yunnan, and other provinces, and Hunan Shimen realgar mine is the largest realgar mine in the world.
Microbial mobilization of arsenic from iron-bearing clay mineral through iron, arsenate, and simultaneous iron-arsenate reduction pathways. Author links open overlay panel Ziwang Zhao a b, Ying Meng a, ... 2013; Tufano et al., 2008). Arsenic mobilization happens when iron (oxyhydr)oxides dissolution is the main process (Fig. …
Gypsum precipitates as a major secondary mineral during the iron-arsenate coprecipitation process for the removal of arsenic from hydrometallurgical effluents. However, its role in the fixation of arsenic is still unknown. This work investigated the incorporation of arsenic into gypsum quantitatively during the crystallization process at …
XRD data processing was done using Jade 6.5 software. The surface charge of the Fe minerals was determined by Zeta Potential Analyzer (Nano ZS90, Malvern, England). 3. ... Arsenate and iron minerals migrated as Fe(II) and As(III) under the effects of intermittent flow. The addition of humic acid effectively inhibited the release …
Arsenate minerals occur in some nickel sulphide ore deposits in a range of minerals like gersdorffite (NiAsS), niccolite (NinAs8 ), rammelsbergite (NiAs 2 ), annabergites (Ni 3 As 2 O 8 .8H 2 O), arsenopyrite (FeAsS), cobaltite (CoAsS), loellingite (FeAs 2 ), sperrylite (PtAs) and other PGE arsenides and sulpharsenides.
Arsenate-reducing bacteria are bacteria which reduce arsenates. ... Arsenates occur naturally in minerals such as adamite, alarsite, legrandite, and erythrite, and as hydrated or anhydrous arsenates. ... 3 with part of the process taking place in the cytoplasm. The arsC gene occurs in ars operons for arsenic resistance in most bacteria and some ...
4.1 Calcium Arsenates. Svabite (Ca 5 (AsO 4) 3F) and other calcium arsenates have been considered for safe arsenic disposal, in treating industry and mineral processing wastes with lime, and it has been assumed that these solids are extremely insoluble and stable [23,36,66–68 ]. Currently this technique has been abandoned as there is evidence ...
Introduction. Arsenic present in mineral-processing solutions and effluents is a major industrial contaminant. It is derived during extraction of metals by oxidation and …
Mining, mineral processing, and pyro/hydrometallurgy are essential activities for the stable supply of metals. These activities, ... As shown in Fig. 5 c, yukonite was formed at pH 8 but was unstable at pH 10, resulting in the formation of ferric arsenate. At pH 12, a new mineral was formed, johnbaumite (Ca 5 (AsO 4) 3 OH) ...
The dynamic mineral–OM interface evolves continuously with changes in the chemistry of aqueous phases, OM and mineralogy, and influences both magnitude and rate of OM adsorption. Observed ...
Mining and smelting operations are an important source of arsenic pollution. Arsenic has long been a problem associated with the extraction of nonferrous metals. …
Mining, mineral processing, and pyro/hydrometallurgy are essential activities for the stable supply of metals. These activities, ... As shown in Fig. 5 c, yukonite was …
Introduction. Arsenic present in mineral-processing solutions and effluents is a major industrial contaminant. It is derived during extraction of metals by oxidation and acid dissolution of the arsenic-containing minerals such as arsenopyrite (FeAsS) and members of tetrahedrite–tennantite series ((Cu,Fe) 12 Sb 4 S 13 –(Cu,Fe) 12 As 4 S 13) in many …
In the bioleaching process of arsenopyrite, arsenic will be dissolved in the form of arsenate. In bioleaching process, a passive film mainly composed of jarosite, elemental sulfur and ferric arsenate will be formed on the surface of the mineral and then inhibit the bioleaching efficiency (Deng et al., 2018b).Since the arsenopyrite itself …
A novel sequential extraction method for the speciation of AsIII and AsV in oxic and anoxic mineral soils was developed and tested. The procedure consists of seven extraction steps targeting various As pools ranging from weakly adsorbed to well-crystalline species. Each step was specifically designed to preserve the AsIII and AsV redox states, …
Mineral processing and metallurgical treatment of lead vanadate deposits stopped in the 1980s, although the deposits contain a noteworthy amount of the desired resource vanadium. ... Arsenate: …
The formation of basic ferric arsenate sulfate and scorodite under these conditions was supported by RSM and confirmed via characterization. In the …
International Journal of Mineral Processing. Volume 157, 10 December 2016, Pages 103-110. The pyrometallurgy of enargite: A literature update. ... The authors also evaluated the possibility of direct formation of ferric arsenate from roaster off-gases in a two-stage fluidized bed reactor, which has been traditionally performed in …
The rate of arsenate reduction was influenced by the method in which arsenate became associated with the mineral phases and may have been strongly coupled with arsenate desorption rates.
Aqueous oxidation of arsenic trioxide or sulfide to arsenate followed by precipitation operations is needed to immobilize the arsenic. In hydrometallurgy operations, arsenic is released into mineral processing solutions and effluents during extraction of metals by oxidation and acid dissolution of the arsenic-containing minerals.
The oxidation and reduction process of arsenate in E. coli and S. cerevisiae is mediated by Pit and Pho87p, ... developed novel organo-mineral composites (nano-zero valent Zn and biochar-hydroxyapatite-alginate) for an effective removal of As(III) and As(V) from the water matrix. Furthermore, ...
The inclusion of arsenate ions into the carbonate site produces changes in the electrical balance and in the cell unit volume of the calcite mineral lattice, so this fact should be partially compensated by the uptake of impurities in the cationic site (e.g., Mg 2+). This mechanism of compensation explains the presence of As in Mg-rich calcites.
The most common mineral species containing arsenic is arsenopyrite . Other minerals such as sulfides and ... Industrial operations such as tannery processing, …
This study has outlined the nature and distribution of the arsenic within abandoned mineral processing buildings at the Ottery mine, New South Wales, Australia. Arsenic at the Ottery mine is hosted primarily in arsenolite-rich efflorescences or in arsenate minerals that precipitate on the exterior surfaces of gypsum-rich efflorescences.
arsenate mineral, any of a group of naturally occurring compounds of arsenic, oxygen, and various metals, most of which are rare, having crystallized under very restricted …
The data obtained show that of 449 approved arsenic mineral species with oxygen, 43% are known from only one or two localities, and 72% are known from 10 or fewer localities. To assess the most common conditions of arsenate minerals formation we selected minerals that were found in more than 200 localities.
the mineral process industries for many years. More recently, because of the recognition that arsenic at low concentrations in drinking water causes severe health effects, the technologies that have been used in the mineral industry are ... arsenate of either form is not thermodynamically stable in the neutral to high pH region (the kinetics of ...
Anthropogenic sources of arsenic include mineral processing, glass manufacturing, wood preserving, pesticide production and application, landfill/waste pile …
Copper concentrates and middlings were used as a source of primary arsenic mineral (such as enargite), in which arsenic occurs as arsenate. Both Cu-sources are …
This section focuses on arsenic mobilization resulting from mining, mineral processing and metallurgical operations. Arsenic contamination of groundwater and soils due to the mining processes occurs globally in places such as: Ghana, Zimbabwe, South Africa, Mexico, Canada and the United States of America (Bissen and Frimmel, 2003a).
