Applications
AGGREGATES FOR CONSTRUCTION
In its broad sense, aggregates are inert solid minerals of classified granulometries, used in formulations with other binders in the manufacture of concrete, asphalt and mortars. They are also used directly in fillers, road firmness (asphalt fabrics or soil stabilizers).
| CONSTRUCTION AGGREGATES | |
|---|---|
| Pill material | 0.5-2 Tn |
| Mortar material | < 40 mm |
| Gravel | 11- 22 mm |
| Sand | < 4 mm |
| Mortar sand | < 2 mm |
REFRACTORY MATERIALS FOR OVEN
There are two main groups of refractories: (1) alumina-based neutrals (clay/andalusite/bauxite); (2) silica-based acids (grs/quartzite/quartz).
Most steel furnaces and foundries are today equipped with magnesium refractories with enormously high melting points (2800 C). Within the range of products for the Iron and Steel Industry, Kelsen Refractories today produces: Dolomia Bricks, Dolomia-Carbon Bricks, Dolomia-Carbon Magnesia Bricks, Magnesite Bricks, Magnesia-Carbon Bricks, Alumina Bricks - , Alumina-Carbon bricks, Dolomite attack and filling masses, etc.
FOOD INDUSTRY: ANIMAL AND HUMAN
Micronized calcium carbonates are used as a food additive in animal feed. In the case of birds, an improvement is achieved in the quality of the egg and the hardness of the shell.
Calcium oxide in very fine granulometry and high reactivity, is used in the production of calcium soaps destined later for the animal feed sector.
These soaps are subsequently marketed, either in solid blocks, or granulated and at the same time mixed with the feed. In this last way, the animal simultaneously assimilates both the feed and the fatty acids necessary for healthy growth.
MEDICINE AND PHARMACOLOGY [SOURCES OF Mg and Ca]
The use of dolomites as a medically prescribed dietary supplement received approval from public health entities in the 1970s.
Advertised health benefits:
- Reduces the effects of osteoporosis
- Improves the Enamel of our teeth
- Improves Joint Health
- Increase Energy Conversion
- Relieves Stomach Acidity
- Strengthens Bones and Teeth
- Helps Reduce Stress Symptoms
INDUSTRIAL AND ORNAMENTAL GLASS
Dolomite represents a critical contribution of alkaline earth elements to silicic melt baths for glass production. The dolomite contributes to the melting bath both Mg/CaO.
This addition supposes:
- Lower the melting point
- Increase the resistance of the glass with the temperature
- Increase the hardness of the glass and its resistance to compression
- Resistance to acid and basic chemical attack
- The gloss, homogenization and polishing of the glass
Raw dolomite with granulometries between 100-500 microns, free (within precise limits) of refractory elements that do not melt at the melting temperatures of the glass bath (1300-1500 C) is commonly used.
In the manufacture of industrial glass, precise limits are established for coloring elements (ferrite, magnetite) as well as for Cr, Co, Mn, Pb, so a precise chemical characterization analysis is required.
CERAMIC
In the ceramic sector, they are an indispensable part of both the filled body of the tile and the glazes that cover them. The heating to which the mineral is subjected during firing allows it to react with the silica and alumina of the clay to form a stable and durable compound.
Dolomitic marbles are very fine-grained natural stones that stand out for their whiteness and uniform shape, which gives them an exclusive naturalness that cannot be achieved with any other artificial derivative.
FERTILIZER
The contribution of calcium and magnesium is essential for the growth of crops. Whitening increases the mineral fertility of acid soils.
Crops need a certain pH to grow optimally. The rains and currently the intensive exploitation of the fields causes an acidification of the land. It is necessary to correct the pH of the soil to maintain its performance throughout the different cycles and agricultural campaigns, for this several products based on lime and calcined dolomite have been designed. Mg is the only metal present in the chlorophyll molecule and essential in the plant-animal biological balance. In the form of raw or calcined dolomite it is used as: Fertilizers in soils poor in magnesium; poorly fertilized soil or excessively potassic soil.
WATER TREATMENT
Different authors have demonstrated the effectiveness of using magnesium hydroxides of low content in environmental technology, both in the purification of waste water and in the remediation of residual soils and solid waste treatment. Likewise, the use of these low-content magnesium hydroxides has also been demonstrated for the recovery of N-NH4+ and P-PO43- contained in waste water, through the formation of struvite and/or phosphates of insoluble magnesium.
NOX/SOX ATMOSPHERIC FILTERS
The hyperreactivity of calcined and sintered MgO in ultrafine granulometry generates an interest in use in filters for the treatment of acidic atmospheric gases (contaminating nitrous and sulphurous oxides) for the control of air quality in urban environments. The retention/absorption characteristics of these filters can be improved from some characteristics of use such as temperature heating, the incidence of ultraviolet light, other dopants, etc.
This is a field open today to experimentation and R&D in the processing of calcined and sintered dolomites and their industrial qualification.
METALLURGICAL SOURCE OF MAGNESIUM
Sea water contains 2.1 g of MgO per liter which with calcined dolomite precipitates Mg in the form of Mg(OH)2 [solubility limit 9 mg/l at 18 C]:
2 CaO + 2 Mg++ + 2 H2O -> 2 Ca++ + 2 Mg (OH)2
MgO + CaO + Mg++ + H2O -> 2 Ca++ + 2 Mg (OH)2
ADHESIVES, CELLULOSE, RUBBER, ABRASIVES ...
More than half of the chemical inputs used in the chemical industry come from carbonates, of which 20-30% are currently dolomites.
The dolomites bring a brilliant luster to the resins. Magnesia is a flame retardant. Like all carbonates, dolomites decrease resistance to impact and fracture. Among the uses that this mineral has in the cosmetics industry, the production of talcum powder, certain facial creams and toothpaste stands out.
The industry consumes calcined dolomite at the rate of 1000 t/year only in the manufacture of toothpaste. The so-called Sorel cement is obtained by mixing MgCl2 and MgO.
In the PRODUCTION OF PAINTS AND ENAMELS, a star product is the so-called "WHITE OF SPAIN".
STEEL FUSION
MgO additions to steel castings lower the melting point to 1400 C, which is achieved by direct addition of dolomite.
The MgO content (6-8%) allows you to control the viscosity properties of the laundry. In the blast furnaces, magnesia is supplied directly with the mineral load with average granulometries (1 mm).
Modern high-capacity steel furnaces with oxygen blowing in several positions and seeking a high productivity of continuous operation (> 100 t/h) assume high consumptions of 15-25 kg of calcined dolomite per ton of steel.
The contribution of dolomite protects the walls of magnesian refractories more effectively from the attack of slag in the initial moments of formation of the wash, which reduces the downtime of the furnace to "coat" the walls.
Thus, demands for dolomite have grown at the same time as steel production.
SPIRITUAL, JEWELRY, COLLECTIBLES
For some potential consumers, dolomite has alternative uses of a spiritual type as a facilitator of meditation associated with zodiac signs, it is a jewelry stone and a collector's item.
