At low RH, thenardite
crystals grow within the drop boundary [125, 127].
The lithology is mainly grey argillaceous salt rock, nitrate salt rock, nitrate argillaceous salt rock, thenardite
salt rock with celadon mudstone, nitrate mudstone, gray salt mudstone, mudstone, and dark brown mudstone, as shown in Table 3.
The mechanical properties of rock samples under monotonic and cyclic loadings were also studied , it was found that under monotonic loading, thenardite
and glauberite samples show an elastic-plastic style; however, under cyclic loading, it changed to a ductile style.
The salicylic acid and methanol (SAM) extraction dissolves alite ([C.sub.3][S.sup.1]), belite ([C.sub.2]S), and free lime (CaO), leaving behind a residue of the tricalcium aluminate ([C.sub.3]A) and ferrite ([C.sub.4]AF) interstitial phases as well as minor phases including periclase (MgO) and alkali sulfates such as arcanite (K[bar.S]), thenardite
(N[S.sub.S]), and langbeinite (K[M.sub.2] [[bar.S].sub.3]), calcium sulfates (gypsum, bassanite, and anhydrite), and carbonates (calcite and dolomite).
The product of the glauberite mine is thenardite
which is an important raw material used in the chemical and light industrial manufacturing industries.
shale, slate, talc, thenardite
, trona, volcanic ash, sand, gravel, clay
Sodium sulphate (thenardite
), though very simple in chemical composition, has been the subject of various applications.
Halite and/or thenardite
could potentially be produced as by-products.
Composition and solubility of some common soluble minerals  Mineral Compound Solubility, mol/l Calcite CaC[O.sub.3] (calcium carbonate) 0.00014 Gypsum CaS[O.sub.4] x 2[H.sub.2]O 0.0154 (calcium sulphate) -- Ca[Cl.sub.2] x 6[H.sub.2]O 7.38 (calcium chloride) Magnesite MgC[O.sub.3] (magnesium carbonate) 0.001 Hexahydrite MgS[O.sub.4] x 6[H.sub.2]O 4.15 (magnesium sulphate) Epsomite MgS[O.sub.4] x 7[H.sub.2]O 3.07 (magnesium sulphate) Bischofite Mg[Cl.sub.2] x 6[H.sub.2]O 5.84 (magnesium chloride) Washing [Na.sub.2]C[O.sub.3] x 2.77 soda 10[H.sub.2]O (sodium carbonate) Mirabilite NaS[O.sub.4] x 10[H.sub.2]O 1.96 (sodium sulphate) Thenardite
NaS[O.sub.4] (sodium sulphate) 3.45 Halite NaCl (sodium chloride) 6.15 Table 2.