Abstract: A method of treating hydroxide alkaline waste and by-products to render the material neutralized or reduced in pH from near 14 to a minimum lower limit of about 5.3 based on aluminum poly cation salts, rendering the waste or by-product stream suitable for ultimate disposal or reuse. The method comprises contacting together a mixture of moderate to high alkaline waste or by-product material with a pH in the range of 7.5-14, with sufficient water added or found within the alkaline material, with one or more poly cationic salts in the dry form taken from a group of salts containing tri-valent aluminum, tri-valent iron, di-valent calcium, di-valent magnesium, di-valent manganese, di-valent zinc, or any polyvalent cationic salt that is soluble in water to a minimum extent of 0.