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About Gypsum
Published in Manjit Singh, Gypsum & Gypsum Products, 2023
The various gypsum and anhydrite differ in purity, structure and colour. The major impurities are calcium carbonate (limestone), dolomite, marl, clay, silica, bitumen, glauberite, syngenite and polyhalite. The impurities which are present from its formation, they are called primary impurities. Secondary impurities are formed during exposure to materials entrapped in to the cracks and leached cavities, but may also be introduced into the rock as waste material during mining. Gypsum is readily soluble in water and therefore rock is leached by surface water. Structurally, gypsum differs from anhydrite. The most important types of native gypsum are flaky gypsum (selenite), fibrous gypsum alabaster (grainy) gypsum, massive gypsum (rocky), porphyritic gypsum, earthly gypsum (gypsite) and gypsum sand i.e., mixed with glauberite salt (Na2SO4.10H2O). Anhydrite always crystalline, can either be sparry (anhydrite spar), coarse to close grained, or even rod shaped. Solubility diagram of systems CaSO4.H2O), Curves A-B.,CaSO4.2H2O), C-D, Orthehombic CaSO4, E-F CaSO4.H2O), Curves A-B CaSO4.2H2O (Kelley, Southard and Anderson) (Kelley, K.K, South-ard, J.C., Anderson, C.T., Tech. Pap. Bur. Mines, Wash, No. 625, 1941.)
Properties of the Elements and Inorganic Compounds
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Name Danburite Datolite Daubreelite Derbylite Diaspore Digenite Diopside Dioptase Dolomite Douglasite Dyscrasite Eddingtonite Eglestonite Emplectite Enargite Enstatite Epidote Epsomite Erythrite Eucairite Euclasite Eudialite Eulytite Euxenite Ferberite Fergussonite Fluorite Franklinite Gahnite Galaxite Galena Galenabismuthite Ganomalite Gaylussite Geikielite Gibbsite Glauberite Glauconite Glaucophane Gmelinite Goethite Greenockite Grossularite Gypsum Halite Hambergite Hanksite Harmotome Hausmannite Haüyne Hedenbergite Helvite Hematite Hemimorphite Herderite Hessite Heulandite Hornblende Huebnerite Humite Formula CaB2Si2O8 CaBSiO4(OH) Cr2FeS4 Fe6Ti6Sb2O23 AlO(OH) Cu1.79S CaMg(SiO3)2 CuSiO2(OH)2 CaMg(CO3)2 K2FeCl42H2O Ag3Sb BaAl2Si3O104H2O Hg4OCl2 CuBiS2 Cu3AsS4 MgSiO3 Ca2Al2FeOH(SiO4)3 MgSO47H2O (Co,Ni)3(AsO4)28H2O AgCuSe BeAlSiO4(OH) (Na,Ca,Ce)5(Fe,Mn)(Zr,Ti) (Si3O9)2(OH,Cl) Bi4(SiO4)3 (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6 FeWO4 (Y,Er,Ce,Fe)(Nb,Ta,Ti)O4 CaF2 ZnFe2O4 ZnAl2O4 MnAl2O4 PbS PbBi2S4 (Ca,Pb)10(OH,Cl)2(Si2O7)3 Na2Ca(CO3)25H2O MgTiO3 Al(OH)3 Na2Ca(SO4)2 (K,Na,Ca)1.6(Fe,Al,Mg)4.0Si7.3Al0.7O20 (OH)4 Na2Mg3Al2[Si8O22](OH)2 (Ca,Na2)[Al2Si4O12]6H2O FeO(OH) CdS Ca3Al2(SiO4)3 CaSO42H2O NaCl Be2(OH,F)BO3 Na22K(SO4)9(CO3)2Cl Ba[Al2Si6O16]6H2O Mn3O4 (Na,Ca)4-8Al6Si6O24(SO4,S)1-2 CaFe(SiO3)2 Mn4Be3Si3O12S Fe2O3 Zn4(OH)2Si2O7H2O CaBe(PO4)(Fe,OH) Ag2Te (Ca,Na2,K2)[Al2Si7O18]6H2O Ca2(Mg,Fe)4Al(Si7AlO22)(OH)2 MnWO4 Mg(OH,F)23Mg2SiO4 Crystal system rhombohedral monoclinic cubic rhombohedral orthorhombic cubic monoclinic rhombohedral rhombohedral orthorhombic rhombohedral rhombohedral cubic rhombohedral rhombohedral monoclinic monoclinic orthorhombic monoclinic orthorhombic monoclinic hexagonal cubic rhombohedral monoclinic tetragonal cubic cubic cubic cubic cubic rhombohedral hexagonal monoclinic hexagonal monoclinic monoclinic monoclinic monoclinic hexagonal orthorhombic hexagonal cubic monoclinic cubic rhombohedral hexagonal monoclinic tetragonal cubic monoclinic cubic hexagonal rhombohedral monoclinic orthorhombic monoclinic monoclinic monoclinic orthorhombic /g cm-3 3.0 2.98 3.81 4.53 3.4 5.55 3.30 3.5 2.86 2.16 9.74 2.8 8.4 6.38 4.5 3.19 3.44 1.67 3.06 7.7 3.1 3.0 6.6 5.5 7.51 5.7 3.18 5.21 4.62 4.04 7.60 7.04 5.6 1.99 3.85 2.42 2.80 2.7 3.19 2.10 4.3 4.8 3.59 2.32 2.17 2.36 2.56 2.44 4.84 2.47 3.53 3.32 5.25 3.45 2.98 8.4 2.2 3.24 7.2 3.3 Hardness n 7 1.63 5.3 1.624 5 6.8 2.8 6 5 3.5 3.8 2.5 2 3 5.5 6 2.3 2 2.5 7.5 5.5 4.5 6 4.3 6 4 6 7.8 7.8 2.5 3 3.5 2.8 5.5 3 2.8 2 6 4.5 5.3 3.3 6.8 2 2 7.5 3.3 4.5 5.5 5.8 6 6 6 5 5.3 2.5 3.8 5.5 4.3 6 2.45 1.694 1.680 1.65 1.500 1.488 1.541 2.49 n 1.63 1.652 2.45 1.715 1.687 1.70 1.679 1.500 1.553
Transformation characteristics of sodium during high-sodium coal combustion process
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Xiaohe Huang, Shouyu Zhang, Fenghao Jiang, Zhongyao Cao, Yifan Zhang, Hao Li, Caiwei Wang
Figure 2 shows the XRD patterns of ZD ash prepared at different combustion temperature. The crystalline of the sodium-containing minerals in the ZD ash are strongly influenced by combustion temperature. As shown in Figure 2, the minerals contained in the ZD ash prepared at 815°C combustion were anhydrite, quartz, sodium chloride, nepheline, and glauberite. The glauberite is poorly soluble in the water and strong acid, but freely soluble in the weak acid (Freyer and Voigt 2004). Therefore, among these minerals, the sodium chloride and glauberite were the soluble sodium, and the nepheline was the insoluble sodium. It can be deduced from the results that the soluble sodium of ZD did not released completely at 815°C combustion. And the sum of the peak intensity of glauberite and sodium chloride was higher than that of nepheline. It can be deduced from the results that the soluble sodium was the main occurrence modes of the sodium contained in the ZD ash prepared at 815°C.
Persulfate activated with calcium peroxide to remediate RAFT soil contaminated with diesel in Arctic northern villages: on-site pilot scale study
Published in Environmental Technology, 2023
Taillard Vincent, Martel Richard, Pasquier Louis-César, Blais Jean-François, Mercier Guy
During the operation, PS was activated prior to its injection. Solid by-products were deposited at the bottom of the RES0 tank under the form of a compacted sludge. At the end of the operational period, air temperature dropped (and so SS stored in RES0) and translucent crystals (1–2 cm in size) assumed to be mirabilite [47] appeared on the oxidizing solution tank walls. These crystals had cumulated with the sludge, which volume reached 52 L with a density of 1.58 g/cm3 and containing about 47% w/w moisture. The dry sludge was composed of 15.4 ± 5.2% calcium, 16.0 ± 5.3% sodium, and 26.8 ± 1.0% sulphur. The high variability of Ca and Na content in the replicates suggested that the sludge was composed of several compounds containing sulphur, and which proportion varied depending on the sample location. Quantitative DRX analysis was carried out on three representative sludge samples and on an unaltered (neither dried nor milled) single crystal. Results confirmed that the crystal deposits were 100% mirabilite (Na2SO4.10H2O), which precipitates depending on temperature, when high concentration of sodium sulphate is reached in solution. The sludge was composed of 47.7 ± 1.7 glauberite (Na2Ca(SO4)2), an anhydrous sodium-calcium sulphate mineral formed in presence of sodium sulphate and calcium sulphate, 32.6 ± 0.4 bassanite (CaSO4.0.5H2O), the hemihydrate form of calcium sulphate, 4.7 ± 4.1 thenardite (Na2SO4) and 14.8 ± 2.7 anhydrous sodium sulphate mineral (Na2SO4).