Glass

Dolomite

Dolomite is a calcium magnesium carbonate mineral with the chemical formula $\text{CaMg}(\text{CO}_3)_2$. It refers to both the specific mineral and the sedimentary rock (dolostone) primarily composed of it. 
 
  • Composition: A “double carbonate” with alternating layers of calcium and magnesium.
  • Identification: Unlike limestone, it reacts weakly with cold dilute hydrochloric acid unless powdered.
  • Hardness: Ranges from 3.5 to 4.0 on the Mohs scale (slightly harder than calcite).
  • Appearance: Typically white, grey, tan, or pink with a vitreous to pearly luster. 
 
 
  • Construction: Used as a concrete and asphalt aggregate, road base material, and in cement production.
  • Agriculture: Applied as agricultural lime to neutralise soil acidity and provide magnesium and calcium.
  • Industrial: Functions as a flux in steelmaking to remove impurities and as a refractory material for furnace linings.
  • Manufacturing: A key ingredient in glass, ceramics, paints, and plastics. 
 

Limestone

  • Main Component: Primarily consists of calcite or aragonite, which are different crystal forms of calcium carbonate.
  • Hardness & Density: Relatively soft, with a Mohs hardness of 2 to 4 and a density ranging from 1.5 to 2.7 g/cm³.
  • Solubility: Slightly soluble in rainwater; this chemical weathering over millions of years creates karst landscapes and caves.
  • Industrial Transformation: When heated to 900–1000°C, it dissociates into lime (calcium oxide) and carbon dioxide, both critical for steel and glass making. 

Aluminum Hydroxide 

  • Commercial Source: Almost all commercial supply is produced from bauxite ore using the Bayer process.
  • Flame Retardancy: When exposed to heat (approx. 200°C), it undergoes endothermic decomposition, releasing water vapor that cools the material and dilutes flammable gases.
  • Chemical Nature: It is amphoteric, meaning it can act as a base to neutralize stomach acid (antacid) or as a weak acid in industrial reactions.
  • Medical Use: Beyond antacids, it is used as an adjuvant in vaccines (like Alhydrogel) to stimulate a stronger immune response. 
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Antimony Products

  • Ore Extraction: Primarily refined from the sulfide mineral stibnite ($Sb_2S_3$) through roasting and carbon reduction.
  • Hardening Agent: Added to lead-acid batteries and bullets to increase the metal’s rigidity and prevent it from deforming under stress.
  • Unique Expansion: Like water, antimony expands upon freezing, a property that ensures metal castings fill every fine detail of a mold.
  • Antimony Trioxide ($Sb_2O_3$): The most critical commercial product, used as a synergist to improve the effectiveness of halogenated flame retardants in textiles and plastics.