Light weight castable refractory

Lightweight refractory is made of refractory light aggregate and powder, binder and admixture. General provisions: the volume density of less than 1800kg/m3 and refractoriness is not required, or
total porosity is more than 45%, at a specified temperature line shrinkage rate of less than 1.5% of the castable, is said for lightweight refractory castable.

Lightweight refractory is characterized by small volume density, low thermal conductivity, so it has good thermal insulation performance. The varieties of light refractory are more, generally according to the light aggregate variety, production method, bond type and performance level, etc… The most commonly used varieties of lightweight aggregate is divided into light sand brick, porous chamotte, hollow spheres, ceramic and expanded prelate lightweight refractory castable.

Energy shortage is the reality of the world today; saving energy is an important task of all countries. In this situation, the lightweight refractory casting material has been developed rapidly, the variety is expanded, the quality is improved and the output is increased. In the past, when the temperature is above 1000 DEG C Furnace in, lightweight refractory castable only as an insulation layer, it is difficult to directly contact with the flame. Now, about 1800 DEG C flame furnace with lightweight refractory castable can production and some can be used as the working lining.

In metallurgy, petroleum, chemical, electric power, building material, etc. industry kiln and thermotechnical equipment, lightweight refractory castable is frequently used, is generally the insulation layer, as well as the working layer or bearing component, good results were obtained. In contact with the molten metal or slag parts, only using tundish insulating board, and achieved good results.

The modulation principle of mud when using refractory bricks

Modulation for bricklaying refractory mortar shall comply with the following principles:

(1) before bricklaying to deal with all kinds of refractory mud of pre experiment and pre laying and determine the different mud bonding time, initial setting time, consistency and water;

(2) The modulation of different mud to use different apparatus, and timely cleaning;

(3) Different modulation to use clean water mud, water should be accurate weighing, to reconcile uniform, adjusted with the use. Has modulated the water is hard and hard and fast and hard mud and water use, has been the beginning of the mud cannot continue to use;

(4) Modulation phosphate bonded slurry to ensure that the provisions of the trapped material time and in tune with the, the slurry has a good modulation may not be any diluted with water. This kind of mud is corrosive and may not be in direct contact with the metal shell.

Refractory material for petrochemical furnace

Chemical and petroleum industry is an important field of application of refractory materials. Due to the thermal furnace more complex operating condition. Therefore, the need for various types ofrefractory materials was selected to fit their specific application conditions. Here, select some of the more prominent examples of special applications for some simple instructions.

(1) Refractory materials for carbon black fuel furnace. In order to improve the production efficiency and the reaction degree, the reaction temperature must be increased in order to improve the production efficiency and the reaction temperature. Again. To produce hard carbon black, but also the need to improve the reaction temperature. In particular, the production of long-life, rolling wear small tires need more hard carbon black, the reaction temperature to reach 2000 ~ 2100 DEG C, which requires more refractory material and adapt.

(2) Slag gasification device. It is well known that the gas industry is widely used in refractories. The operating temperature and pressure of the refractory material used in the gasification equipment areextremely harsh, and the operation temperature and pressure are high: the slag belongs to the acid slag which has very strong corrosion resistance. At the same time, there is a highly corrosive gas. Refractory materials used for high resistance to acid slag corrosion can be used to obtain high life.

(3) The oil cracking unit: the operating conditions in the catalytic cracking unit are the most demanding operating conditions, including high temperature and high pressure. The refractory material used in the catalytic cracking unit is required to have high wear resistance and low thermal conductivity so that the two contradictory properties.

New building materials-Basic refractory

Alkaline refractory materials mainly refers to the oxidation of magnesium, calcium oxide as the main component of the refractory, the alkaline slag has a strong anti – erosion ability. Including magnesia brick, magnesia brick, magnesia chrome brick, dolomite brick (see magnesia brick).

Commonly used is brick. Containing magnesium oxide 80% ~ 85% of magnesia brick, on the basic slag and iron slag has good resistance, refractoriness than clay brick and brick. Mainly used in open hearth furnace, oxygen converter, electric furnace, non-ferrous metal smelting equipment and high temperature equipment.

Characteristics of basic refractory materials

Inorganic non metallic materials with fire resistance higher than 1580. Refractoriness refractory cone specimen under no load, resistance to high temperature and not softening melting down Celsius temperature. Refractory materials and high temperature technology, which originated in the middle of the Bronze Age. In the Eastern Han Dynasty has made China kiln firing porcelain material and with fireclay refractory sager. At the beginning of twentieth Century, the refractory materials were developed in the direction of high purity, high density and ultra high temperature, and there was no need to burn, and the energy consumption is small. Modern, with the atomic energy technology, space technology, new energy technology development, with high temperature resistance, corrosion resistance, thermal shock resistant, resistant refractory material erosion comprehensive excellent performance has been applied.

Refractory material in steel making system

The steelmaking system includes a converter, electric furnace, furnace, ladle, ladle and tundish. Ladle and tundish is an important auxiliary equipment of the steel making furnace, and also the most important equipment for the use of refractory materials.

In the converter and electric furnace, the general use of refractory spray paint repair, the method is manual cast refractory materials, wet, dry or flame spraying and slag splashing furnace, etc…

In the electric furnace, the dry vibration material of the refractory material, the pre cast or cast in place or the furnace cover: triangle area and other parts are better use effect.

In the converter, the widespread adoption of slag splashing furnace maintenance technique and the service life of furnace can reach more than 10000 times; outside furnace refining furnace are more, the RH process and the method of DH degassing device insertion tube lining of the body, generally with high aluminum refractory  material is poured into a whole, the service life is 20-80 times.

Damage reason of refractory

According to the specific conditions of various furnaces and thermal equipment, proper selection and application of refractory material is very necessary. It is to improve the service life of the kiln and thermo technical equipment, reduce maintenance time, reducing the consumption of refractory material and energy, improve furnace production and guarantee the quality of the products and reduce the cost of production plays an important role.

As is known to all, there will be some damage reasons for different kinds of kilns or thermal equipment under different working conditions. Even in different parts of the same furnace or thermal equipment. There are many factors that affect the damage of refractory materials:

(1) The use of the temperature is too high, exceeding the limit temperature of the refractory;

(2) The temperature changes in temperature, refractory material damage in blast crisis;

(3) The refractories by slag furnace, mechanical shock or friction and wear serious the damage;

(4) The refractory material is damaged by the high temperature physical and chemical erosion and penetration of the molten metal, slag and furnace gas;

(5) The thermal stress and the weight of the heat generated by the heat of the refractory material cause damage to the stress concentration and the volume effect.

The above factors are not isolated, only to find out the main influencing factors in order to correct selection of refractory materials.

Insulation materials used in power plant

Thermal insulation refractory material in the electric power industry especially thermal power plants, such as coal-fired power plants occupies an important position. It has energy saving, reduce heat loss, to meet the requirements of the power plant production process, ensure theequipment, production and personal safety, improve the environment, improve the economic benefit, is an important part of the construction of power plants. So the power plant is commonly used in the refractory material is light heat insulation brick. According to the present and future development, electric power industry of insulating refractory material demand quantity big, more varieties, high quality requirements, which the fiber insulation refractoriness demand maximum, followed by hard material, and is lightweight materials and thermal insulation coating.

One, according to the various parts of the heat preservation refractory materials of the insulation requirements of choice

(1) The medium temperature of the equipment and the pipeline at 350~600 is chosen to use calcium silicate products, aluminum silicate composite insulation;

(2) with rock, mineral wool products such as insulation equipment and piping medium temperature less than 350 DEG c;

(3) The valve, elbow and other special-shaped pieces of light insulation material or heat preservation coating insulation;

(4) The use of ordinary aluminum silicate fiber rope insulation is less than 38mm;

(5) The low temperature equipment and piping in the wet environment are chosen for the insulation of the hydrophobic insulation material