Gypsum is soluble in hot diluted HCl. How about anhydrite? is it soluble in 12 N hcl, diluted HCL? or need to use HNO3
Dear Jingqiang,
I recommend you these papers.
Good Luck
Li, Zhibao, and George P. Demopoulos. "Development of an improved chemical model for the estimation of CaSO4 solubilities in the HCl-CaCl2-H2O system up to 100 C." Industrial & engineering chemistry research 45.9 (2006): 2914-2922.
Li, Zhibao, and George P. Demopoulos. "Effect of NaCl, MgCl2, FeCl2, FeCl3, and AlCl3 on solubility of CaSO4 phases in aqueous HCl or HCl+ CaCl2 solutions at 298 to 353 K." Journal of Chemical & Engineering Data 51.2 (2006): 569-576.
Li, Zhibao, and George P. Demopoulos. "Solubility of CaSO4 phases in aqueous HCl+ CaCl2 solutions from 283 K to 353 K." Journal of Chemical & Engineering Data 50.6 (2005): 1971-1982.
Azimi, G., V. G. Papangelakis, and J. E. Dutrizac. "Development of an MSE-based chemical model for the solubility of calcium sulphate in mixed chloride–sulphate solutions." Fluid Phase Equilibria 266.1 (2008): 172-186.
Li, Zhibao, and George P. Demopoulos. "Model-based construction of calcium sulfate phase-transition diagrams in the HCl-CaCl2-H2O system between 0 and 100° C." Industrial & engineering chemistry research 45.13 (2006): 4517-4524.
Flint, Oliver. "Increased solubility of calcium sulphate in sea water containing hydrochloric acid." Desalination 4.3 (1968): 328-335.
Li, Zhibao, and George P. Demopoulos. "Speciation-based chemical equilibrium model of CaSO4 solubility in the H+ Na+ Ca+ Mg+ Al+ Fe (II)+ Cl+ SO4+ H2O system." Industrial & Engineering Chemistry Research 46.20 (2007): 6385-6392.
Zhong, Yin, and Zhao Xiao-Dong. "SOLUBILITIES OF CALCIUM SULFATE IN HYDROCHLORIC ACID AND AQUEOUS SODIUM CHLORIDE SOLUTION [J]." OILFIELD CHEMISTRY 4 (1994).
Wang, Wenlei, et al. "Experimental determination and modeling of gypsum and insoluble anhydrite solubility in the system CaSO 4–H 2 SO 4–H 2 O." Chemical Engineering Science 101 (2013): 120-129.
Puchelt, Harald, and I. Jenny Setiobudi. "New dissolution technique for rarely soluble sulfate minerals for AAS and ICP investigations." Fresenius' Zeitschrift für analytische Chemie 335.7 (1989): 692-694.
Wang, Wenlei, et al. "Experimental Determination and Modeling of the Solubility of CaSO4· 2H2O and CaSO4 in the Quaternary System CaSO4+ MgSO4+ H2SO4+ H2O." Industrial & Engineering Chemistry Research 53.32 (2014): 12839-12847.
Bhagawati, Dhrubajyoti, et al. "Study on the Effect of pH, Ionic Strength and Pressure on the Solubility of CaSO4-NaCl-H2O System."
Wang, Wenlei, et al. "Solubility Isotherms of Gypsum, Hemihydrate, and Anhydrite in the Ternary Systems CaSO4+ MSO4+ H2O (M= Mn, Co, Ni, Cu, Zn) at T= 298.1 K to 373.1 K." Journal of Chemical & Engineering Data 60.10 (2015): 3024-3032.
It depends, if you want to do detailed geochemistry, then you need to dissolve it in HNO3 or HF+HNO3
Dear Dr. Tan,
there is a simple answer. Anhydrite (powdered) is soluble in hydrochloric acid (HCl), but only with little effect in water. It hydrates over longer period of time < 42°C and turns into gypsum. You need no "hard dissolvents" to decompose this sulfate under laboratory conditions and you can use acid you mentioned above. If you want to carry out differential leaching and save other minerals, the procedure has to be adjusted pH-wise. I do not know the matrix and your goals of study.
Best regards
H.G.Dill
The solubility of calcium sulphate in water can be increased several times through the ion pairing effect, i.e. by addition of a soluble salt of a kation that has high affinity to sulphate, (forming an ion pair). For some analytical purposes, we have used pre- cleaned magnesium nitrate solutions. With "cleaning" we mean using ion exchange to remove the trace elements we are interested in (so that all comes from the gypsum/anhydrite). However, for most geochemical analyses, 1 M HNO3 has proven satisfactory. If pH is increased, gypsum will precipitate.
Dissolution and conversions of gypsum and anhydrite were illustrated in the following chapter
Chapter Dissolution and conversions of gypsum and anhydrite
Best Regards Jingqiang Tan
Hi Prof. Dr. Harald G. Dill,
What should be the best experimental schematics for the removal of anhydrite from lithium slag (LS) using HCl or HNO3, without significantly altering the rest of the mineral phases in LS.
For your reference, LS contains Alumino-silicates in the form of spodumene, anorthite, and albite along with calcite.
Thanks in anticipation.
Fine-grained particles can be dissolved in conc. H2SO4 which is, however, not the method of choice for samples intended to be used for further laboratory trials in sedimentology or metallurgy because it is harming mineralogically the residue. Water has no effect. It is much better to grind your slags and use 10 % hydrous NaCl solution, put it into a container and shake it with a shaking machine for 24 hrs. You can remove both gypsum and anhydrite. The method was elaborated by the late German professor of sedimentology (specialist in salt deposits), Prof. Dr. Correns.
Good luck !
HGD
You may consider aq. sol. of ethylenediaminetetraacetic acid (EDTA) adjusted to pH = 10 with NaOH aq.
- Badges
- Science topic
- Similar topics
- Methodology
- Research Methodology
- Research Papers