On the emergence of the efflorescence (whitening) building stone surface cleaning Old buildings or new buildings have emerged when the pan-alkali phenomenon, should be cleaned up before hanging Shanxi black stone, whether it is easy to appear pan Alkali wet hanging method, or not prone to pan-alkali hanging method, as long as the building is not hanging when the emergence of the phenomenon of pan-alkali, have to be cleared. Because the wet sticky stone alkaline will be passed directly to the stone outside the decorative surface; and dry hanging stone, although the transfer of dried pendant relative to the transfer of alkali is not so easy, but the connection of the stone pipes, rain, snow and fog will lead the main building substrate Alkaline into the stone, the surface of the stone appear.
Specific approach is soluble in water, alkali metal salts, such as Na2 SO4, K2 SO4, CaCO3, etc., can be directly scrubbed with water, the conditions available high pressure water gun, if you do not know the basic components of the substrate, as long as Does not affect the construction, safety and environment can be washed several times with water; in case of large areas of CaCO3 deposition, high pressure water jet does not help (small area available fine sandpaper), you can use sandblast gun removal, the use of fine sand abrasive, the best Select more than 80 mesh fine sand, the conditions should be tested fine sand hardness, the best hardness between the substrate hardness and the base between the alkali, neither destroy the main building surface, but also remove the base.
As above removal methods can not be cleared, you can use low acid solution cleaning, it is best to choose a special stone-based alkaline cleaning agent. Acidic solution try to use low acid acid, such as oxalic acid, hydrochloric acid. Oxalic acid solution can be converted into oxalic acid: water -1: 2 solution; hydrochloric acid can be converted into hydrochloric acid: water -1: (10 ~ 15) dilute hydrochloric acid solution. Preparation should pay attention to protective procedures. In order to prevent the building surface from drying, and there are holes, fissures, a large number of acid absorption, so wash with acid before the building surface should be saturated with water holes, it can prevent the acid into the hole to react to generate soluble salts produced again Bleaching, or to promote the infiltration of dilute acid inside the black building in Shanxi and embedded parts, steel reaction, the formation of rust, macular.