Stone casting is produced by melting rocks close to basalt and pouring them into earth or metal molds, as well as by centrifugal casting methods.

Such parameters as high wear resistance, acid and alkali resistance, heat resistance in combination with high mechanical characteristics allowed stone casting to become an indispensable material when working in harsh operating conditions, under the influence of aggressive media, abrasive impact, high temperature, humidity, dustiness, mechanical loads.

Under constant influence of the above factors stone casting products show themselves to be more workable and durable than products made of such traditional materials as steel, cast iron, reinforced concrete, refractories. If we also take into account that the cost of 1 ton of stone casting products is lower than the same product made of metal, but at the same time the specific weight of stone is 2.7 times less than steel, then its use in addition to improving the operational properties is also a significant economic prospect.

Today such material is widely used for making liners, which are used for lining large diameter pipes for ash-slag-slag pipelines; for pneumatic feeding of bulk materials; for making chutes, channels, leaks; for protection of equipment from abrasive and chemical impact; for lining of cyclones and hydrocyclones and many other things. In this case the service life of equipment is significantly increased, metal and other expensive materials are saved, the inter-repair period of equipment operation at enterprises is increased.

Stone castings are made of several types depending on the requirements for operation. The most widely used is wear-resistant casting (operating temperature up to 200 degrees C). It has the best performance in terms of wear resistance, acid resistance and mechanical properties. Heat-resistant castings have operating temperature up to 700°C and higher, high resistance to temperature fluctuations, but they are somewhat more expensive than wear-resistant. There are also some types of stone castings with special properties.

Table 1 clearly shows that by such characteristics as abrasion coefficient, acid resistance, hardness and water absorption, stone casting significantly exceeds traditional materials. According to the Moas hardness scale stone casting has 7÷8th group, inferior only to diamond and corundum.

An indicator limiting the operational capabilities of stone casting is increased brittleness (low impact toughness). Brittleness is reduced by reinforcing the products with metal meshes or using embedded elements. This quality should be taken into account when designing new stone casting products.

As can be seen from Table 3 stone casting is resistant to almost all acids, except hydrofluoric acid. It should also be noted good resistance of stone casting in molten aluminum.

In addition to those listed above, it is possible to designate a number of other positive properties of stone casting:

• Resistance of stone casting to destruction as a result of thermal stresses (thermal resistance) at temperature differences in the range of 20-700оС according to GOST 6145-55 for heat-resistant stone casting - not less than 20 heat exchanges;
• The coefficient of thermal diffusivity, which characterizes the rate of temperature propagation in the material for wear-resistant and heat-resistant castings is 1.24x103 m2 /h (at temperatures up to 100 0C) and 3.22x103 m2 /h (at temperatures up to 700 0C);
• Dielectric properties of stone castings:

1. specific volume electrical resistance - 1.7-3.0 105 -OM-m
2. dielectric strength - 0.8-3.0 kV/mm
3. dielectric permittivity, at f=50 Hz - 0,095-0,13
4. dielectric properties can be improved by reducing iron and manganese content in stone casting or by using light stone or dolomite casting;

• Stone castings are not subject to aging - their properties do not change over time;
• Stone casting, when interacting with radioactive substances, effectively traps radiation and does not produce radioactive dust.

Analysis of equipment and structures of mining enterprises, metallurgy, as well as other industries, exposed to abrasive wear, aggressive media and elevated temperatures, has shown that most of the equipment surfaces are not protected or protected by ineffective materials from the destructive effects of the working environment; more than 90% of the area of equipment and structures operate at pressures less than 5 MPa.

By its strength properties stone casting withstands loads significantly exceeding 5 MPa and therefore can be widely used to protect equipment from abrasive wear, the impact of aggressive media and elevated temperatures, which is confirmed by many years of practice of stone casting products in various industries, providing an increase in the service life of equipment up to several tens of times.

At Novo-Krivorozhskiy GOK more than 10 years operated stone-cast slurry pipeline 600 m long. 800 and 500 mm cross-section, while the metal one served no more than 2 years.

At application of stone-cast chutes their wear makes 1 mm per year, while metal wears 6-10 mm.

Hydrocyclones lined with stone casting are superior in their performance characteristics to cast iron ones lined with rubber or polyurethane. Stone-cast multicyclones in air purification systems at enrichment plants serve for more than 10 years without significant wear.
At metallurgical plants stone products are used for lining of coke funnels and coke hoppers. The wear of this lining per year is 2-2,5% (by thickness), while manganese steel of 40 mm thickness wears out in 1-1,5 years. Such lining is used at Donetsk Iron and Steel Works, Novo-Lipetsk and Kuznetsk Iron and Steel Works. In rolling shops stone troughs are used in the systems of scale washing.

Scale washing systems equipped with stone troughs are installed at Magnitogorsk Iron and Steel Works, Asha Iron and Steel Works, Pervouralsk Novotrubny Zavod, Abinsky Electrometallurgical Plant.
Block multicyclones with elements made of stone castings are used for purification of exhaust gases at sintering machines. Compared to cast iron elements they are less bulky, due to low resistance of element walls separation of exhaust gases from dust-like particles is more
more technologically.

In the industry of non-ferrous metals stone casting is used for lining of separate units of flotation machines, slurry pipelines of the 1st stage of raw materials grinding, classifiers, hydrocyclones, receiving sump of pumps and samplers, classifiers, contact vats, chutes, leaks between flotation machines, telescopes of plate feeders, floors under oil systems, etc.

The sand chute of the rack classifier, lined with stone slabs, was operated at the processing plant of Balkhash MMC. Such lining serves more than 3 years in comparison with 6 months of metal lining. At the same place in the drying-filtering shop wet scrubbers protected with stone slabs serve about 2 years, while metal ones worked not more than 2 months.

In the aluminum industry stone casting replaced asbestos protection of electrolysis baths, and in the systems of pneumatic and hydraulic supply of components and solutions pipes Ø 159-325 mm with internal lining with stone casting are used.

Open tailing pipes and leaks at factories and quarries are also lined with stone casting, which allows to significantly increase their service life.
A vertical slurry pipeline was installed at OJSC KMA-Ruda Combine in 2008 to pump slurry effluent into mine voids to a depth of more than 600 meters.

At coal preparation plants hydrocyclones lined with stone casting are used, which are more efficient by their operational properties than hydrocyclones lined with other materials (wear-resistant cast iron, rubber, polyurethane, etc.).

Protection of chutes, leaks and slurry water pipelines by stone casting is the most effective. At one of combines of OJSC "Kuzbassugol" with the help of stone-cast pipeline 30-35 thousand m3 of material is delivered to the preparation plant, while the metal pipeline was leaking 6 thousand m3 of material and was out of operation.

The most widespread application in this industry has found heat-resistant stone castings for lining of coke ramps and hot coke feeding systems (leaks, funnels, etc.). Thus, it was possible to avoid expensive stainless steel and lead linings while maintaining operational characteristics. Cheaper substitutes - cast iron, slag-stone castings were used for a much shorter period between repairs, which led to increased repair costs.

Lining of tanks of vessels and cisterns with stone castings allows to reliably protect expensive equipment from aggressive liquids.
As in the rest of the industry, stone-cast pipes are effectively used to convey aggressive liquids.

For many years, pneumatic pipelines protected with wear-resistant stone castings have been used to supply powdered fertilisers (nitrogen, phosphate, compound fertilisers, etc.) at mineral fertiliser plants such as Acron, Balakovo Mineral Fertilisers, Phosphorit and others.

There is experience in using basalt bricks as load-bearing structures in adsorption towers, which gives a significant economic effect in comparison with stainless steels.
It is also recommended to protect aggressive gas removal and supply systems (including pipes, gas ducts, chambers) with stone castings to increase their service life.

Systems of stone cast chutes for gravity ash removal are installed at many thermal power plants - at Khabarovskaya CHPP-3, Ust-Iliimskaya CHPP, Sosnovoborskaya CHPP and at a number of power engineering facilities.

In 1997 at Kumertauskaya CHPP of OJSC "Bashkirenergo" the stone casting lining of the grinding fan smoke pump was made. Without stone casting lining, the smoke pump was in disrepair every 2-3 months. After modernisation of this equipment, annual inspections for 14 years showed no significant wear.
Scrubbers and Venturi pipes are lined with tiles or special stone cast fittings, which allows these products to be safely protected in the most hazardous areas.

In pneumatic ash conveying systems, lining of pipelines with stone castings has increased their service life by 5-8 times. The same can be said about stone-cast nozzles. There are also developments of containers for storage of spent nuclear fuel for nuclear power plants, as stone castings may not interact with spent nuclear fuel for a long time and do not create radioactive dust. The stone-cast inner shell of such containers makes it possible to keep radioactive substances from interacting with the environment.

For longer service life, stone castings are used in cyclones, gas ducts, air purification elements.

There is also experience of using stone castings in leaks and chutes for feeding bulk materials.

In 1998 at Sukholozhskiy refractory plant a pipeline lined with stone casting was installed for return of substandard chamotte to the ball mill for milling. After 12 years there is virtually no wear. Prior to this, the unprotected cast stone pipework was replaced twice a year.

Light stone casting is widely used in construction. Light stone slabs are used for facing public buildings, overpasses, granite and marble can be replaced in the manufacture of plinths, cornices, staircase steps. It is interesting to use light stone slabs for facing the underground.

Acid-resistant cements based on acid-resistant powder - grinding of stone casting - are used as binding compositions in the manufacture of apparatuses for chemical industries. Acid-resistant concretes and putties are used in all branches of industry.

Due to the fact that concrete protection of coastal fortifications against sea waves is not durable, it is used to clad with stone castings.

In agriculture - floors for cattle pens in slaughterhouses, roof gutters, lining of chutes and silage towers.

In the food industry, stone castings are used to line the floors of breweries, dairies, confectionery factories and meat processing plants. It is possible to use stone castings for lining beet washers, feeding chutes, cutting platforms.

In pulp and paper industry stone castings are suitable for lining of digesters, pipelines for aggressive waste water, etc.

In the transport industry, stone castings can be used to make bridge foundations, linings, tunnel segments, road kerbs, etc.

Special containers for burial of spent nuclear fuel have been developed for the nuclear industry.