Clay

Clay called earthy mineral mass, or earthy clastic rocks which may form a dough with water, drying preserves to give it shape without cracking and shrinkage, and after firing the acquiring firm stone. The most important mineral is kaolinite glinoobrazuyuschim Al203, 2Si02-2H20 - aqueous aluminosilicate, consisting of minute particles of flake shape of less than 0,005 mm. The grain size of dust 0,005 ... 0,15 mm and sand - 0,14 ... 5 mm. Clay minerals are well absorbed and retain on their surface moisture. Clay-rich clay minerals are called "fat"; much sanding clay called "lean", they are easily dried, have a low shrinkage, no cracking, but the ductility and strength of their lower than that of the "fat" clays. In "Fat" clays are introduced emaciated supplements - sand, slag, sliced ??straw, fire and other white clay containing many of kaolinite, called kaolin. From kaolin and additives produce porcelain and faience. Color of the clay depends on the impurities: iron oxides and manganese oxides reported clays red, yellow or brown, organic impurities (humus) - Black. The use of clay is very diverse: for the production of building ceramics, refractories, pottery, porcelain, as a component of the raw mix in cement production as air binder in masonry and plaster, as a plasticizer for cement and other building solutions. Clay only partially can be attributed to simple mineral astringent air hardening. When mixing clay with water formed plastic clay dough, adding sand - glinopeschany mortar. As the dough, and the solution over time harden, but not by chemical reactions between clay and water, and not as a consequence of physical and chemical processes, and through evaporation of water, ie drying test and solution. Naturally, no tumor is not formed. After drying, the clay dough and a solution is obtained very strong (up to 100 kg/cm2), a stone, but before the first contact with water. In water, soak a clay stone falls apart. With a moderate amount of water re-formed clay dough, which can bind the grain of sand and gravel. Walls of dwellings trowel, both inside and outside glinopeschanym solution. Absolutely indispensable clay solutions for masonry stoves and pipes. The use of clay as a binder in masonry stoves and pipes based on its properties that, at elevated temperatures, the clay is gaining strength, while the other binders, in this case it reduces. Brick walls of raw wood and adobe clay mortar trowel. Ordinary clay is not recommended for preparation of solutions used in masonry and plastering in wet operating conditions. At temperatures below 0 ° C, the clay swells and increases in volume, resulting in brickwork loses its strength and density. Therefore, the clay solution should not be used for masonry chimneys headroom, and exterior walls of the flue and air ducts, as well as foundations for furnaces, fireplaces and chimneys are indigenous. In the furnace towards the clay used in the form of solutions. For solutions used in different parts of the masonry stove, use a common, refractory and fire clay. Common, or red, the clay used for the preparation of solutions, going to the clutch array of stoves and fireplaces, were made of ordinary clay bricks. On masonry firebox, and vaults dymooborotov stoves were made of refractory bricks, using solutions of refractory clay mixed with sand. Refractory fireclay bricks are placed on the solution of the refractory clay, and the solution instead of sand was added ground chamotte in a 1:1 ratio. When mixing water clay is markedly increased in volume to form a dough. Drying and firing of its volume is significantly reduced. Plasticity of the clay depends on the amount of impurities, particle size of clay substance, water absorption and other factors. In the process of shrinkage clay medium plasticity is reduced in volume by 6 ... 8%, the skinny - less than 6%. Fat content of clay is approximately determined by bulk weight and number of impurities of sand. When volumetric mass 1300 ... 1400 kg/m3glina is oily, at 1450 ... 1500 kg/m3- the middle and at 1500 ... 1600 kg/m3 - skinny. Rich clay contains impurities, 2 .. .3% Sand, the average - about 15% lean - about 30%. Clean impurities from the clay used for the manufacture of refractory products. The quality of the clay depends on its plasticity (fat) that can be checked by touch. Loam forms a dough, soft and fat, like lard or soap. Its plasticity can be checked in another way. Clay make a flagellum thickness of 15-20 mm and a length of 150-200 mm and pull him by the two ends. Flagellum of lean clay (loam) is stretched a little, and place it breaks formed jagged edges. Medium plasticity clay is pulled smoothly and ends when the thickness at the site of rupture is equal to 1 / 5 the diameter of the flagellum. Flagellum of plastic clay is pulled smoothly and gradually thins, forming at the site of sharp ends. If the molded and dried pottery burn at a temperature of 900 ... 1100 ° C, they become water-resistant and highly durable ceramic materials - bricks, tiles, pipes, tiles, etc.