Acid throwing and readily available in many instances. For example, often acid throwers can purchase a liter of concentrated sulfuric acid at motorbike mechanic shops for about 40 U.S. cents. Nitric acid costs around $1.50 per liter and is available for purchase at gold or jewelry shops, as polishers generally use it to purify gold and metals. Hydrochloric acid is also used for polishing jewelry, as well as for making soy sauce, cosmetics, and traditional medicine/amphetamine drugs. Due to such ease of access, many organizations call for a stricter regulation on the acid economy. Specific actions include required licenses for all acid
Acid mine drainage mode-of-action is quite different from limestone, the ability of calcium silicate to neutralize acid solutions is equivalent to limestone as evidenced by its CCE value of 90-100% and its relative neutralizing value of 98%. In the presence of heavy metals, calcium silicate reacts in a different manner than limestone. As limestone raises the pH of the bulk solution, and if heavy metals are present, precipitation of the metal hydroxides (with extremely low solubilities) is normally accelerated and the potential of armoring of limestone particles increases significantly. In the calcium silicate aggregate, as silicic acid species are absorbed onto the metal