lava stone is also a very good building decoration material. It can be widely used for indoor and outdoor decoration. It is mainly used for outdoor stone. Its natural design and color can be well coordinated with the surrounding landscape. It is very suitable for outdoor landscape construction, especially for outdoor landscape construction. The best choice for laying stones.
lava stone is the best material for repairing the runway of highway, railway and airport. It has strong compressive resistance, low crushing value, strong corrosion resistance and asphalt adhesion basalt. lava stone has the advantages of wear resistance, less water consumption, poor electrical conductivity, strong compressive resistance, low crushing value, strong corrosion resistance and asphalt adhesion, and is internationally recognized. It is the best cornerstone for developing railway transportation and road transport.
lava stone is a good raw material for producing "cast stone". "Cast stone" is a material made of melting, casting and annealing of basalt. It is harder and more wear-resistant than alloy steel, and is more resistant to corrosion than lead and rubber. Basalt also acts as a "lubricant" in an advanced steel casting process, which can prolong the life of the cast film. At the same time, the basalt can also be drawn into glass fiber, than the general glass cloth alkali resistance, high temperature resistance.
Among them, the porous lava stone, also known as pumice, has many pores and hard texture. It can be mixed into concrete to reduce the weight of concrete. It is not only strong and durable, but also has the characteristics of sound insulation and heat insulation. It is a good aggregate for lightweight concrete in high-rise buildings. Pumice is also a very good grinding material, can be used to grind metal, abrasive stone; in industry can also be used as filters, dryers, catalysts and so on. It is also widely used in landscape gardens, mainly for rockery, bonsai and so on, but also for home decoration.
The degree of crystallization and grain size of lava stone depend mainly on the cooling rate of magma. Slow cooling (e.g. several degrees a day) produces large crystals of several millimetres in size and size; rapid cooling (e.g. 100 degrees a minute) produces fine needle-like, plate-like crystals or amorphous glass. Therefore, under surface conditions, basalts usually have fine to cryptocrystalline or vitreous textures, and a few of them are granular textures. It often contains olivine, pyroxene and plagioclase Shi Banjing, forming porphyritic structure. Phenocrysts can be aggregated in mobile magma, known as the spotted structure. These phenocrysts are formed during the ascent of basalt magma through the earth's crust (which takes months to hours) and also in huge magma reservoirs before eruption. With the thickness of the rock flow, the cooling rate and the amount of volatile components, there are various transition types between the whole crystalline and vitreous, but the main structure is meso-granular structure, filling structure, hidden structure, less secondary diabase structure and diabase structure.
According to SiO2 saturation and alkalinity, lava stone is divided into two categories:
(1) tholeiitic basalt (subalkaline basalt) is SiO2 supersaturated or saturated rock. It contains no olivine and nepheline, and is characterized by orthopyroxene and variable pyroxene. The relationship between SiO2 and total alkalinity is (Na2O+K2O) / (SiO2-39) value less than 0.37.
Alkaline basalt, SiO2 is unsaturated and alkali rich. Olivine and accessory feldspar (such as nepheline), zeolite, etc., the latter two minerals sometimes with alkaline feldspar or potassic medium feldspar, potassic feldspar, as a filler in the matrix; no clinopyroxene, variable pyroxene, only rich in calcium clinopyroxene, that is, diopside ordinary pyroxene. The value of (Na2O+K2O) / (SiO2-39) is greater than 0.37.
The color of lava stone is usually black, dark brown or dark green, and the color of lava stone near Tengchong volcano group is mostly cyan-grey, but also dark red, orange, yellow. Because of its dense texture, its specific gravity is heavier than that of ordinary granite, limestone, Sha Yan and shale. But there are also some lava stone because of the large number of stomata, the weight will be reduced, and even float in water.