Production of xylolith (rockwood). Sorel magnesia cement is obtained from ground burnt caustic magnesite prepared with magnesium chloride solution. By adding aggregate to Sorela cement (as a filler in the form of flour) you get xylolite or rockwood; it is a self-bonding material, it was used to make floors in indoor spaces (inside buildings). Xylolite floors stand out, fire resistance, indelibility, thermal impermeability; are compressive strength (200—300 kg/m2), but not very resistant to weather conditions, water, acids, rules.
Building elements exposed to acids are covered with acid-resistant mortar or acid-resistant coating, or it is made entirely of acid-resistant concrete. The composition of the acid-resistant mass (cakes) they come in: 1) acid-resistant aggregate for mortars - clean quartz sand, containing at least 97% Si02, confused in proportion 1:1 with quartz dust; for concrete - dust and quartz sand as above, with the addition of granite grit, andesite or clinker; for coatings - quartz sand, ground into a flour; 2) acid-resistant binder - water glass with the coefficient n = 2.5-3 and in water solution 35-38 ° Be (water glass, as having multiple applications in construction), 3) catalyst accelerating hardening of the acid-resistant binder - sodium fluorosilicate, described later in this chapter. Ingredients for acid-resistant dough, -namely aggregate, water glass, sodium fluorosilicate is taken in proportion 4:1:0,15. The beginning of binding of the dough occurs after 40 min. do 1 at, end - after 12 do 16 at. Strength after 28 days (acidify when stored in hot and cold conditions) 60 kg / cm2 in compression and 18-20 kg / cm2 in burst. Mortars, concretes or such coatings are resistant to corrosive acids of inorganic origin, with the exception of hydrofluoric and phosphoric acid at concentrations up to 40%. Organic acids are almost destructive to them.