Refractory castable using validity period and size selection

一、Using effective period

Need watering tie with monolithic refractories, such as high temperature cement, refractory plastic, refractory castable, etc., must be checked before use its expiry date. Exceeds the material period, its performance will decline.

Unpacking refractory castable pocket, be sure to carefully view the manufacture date on the bag. Such as alumina cement shelf life of 3 to 6 months, cement vulnerable to air humidity during storage and transport and curdle, must be strictly checked.

Refractory soft plastic blank group, due to solidification into lumps, you can not using.

二、Granularity refractory castable

Refractory castable granularity shape, strength, size and composition, the quality of the masonry has a very important influence.

Check granularity shape, generally use visual methods. Such as knotted crucible induction furnace lining was prismatic granularity best with sharp corners. Check granularity intensity can be struck with a wooden hammer, watching the situation to determine its smash.

Check the size and composition of the particle size, the use of screening method. Sieving is carried out in the test chamber, which can be measured by the percentage of various particle size of the composition.

First check pattern according to the technical requirements of the stove on, pay attention to the size of the maximum size limits, and secondly to fire clay should be careful not lost too many fine parts, so as not to reduce its masonry performance.

The question of how much the proportion accounted for cement in castable refractory

In the use of castable refractories, cement is added in a certain proportion, if not add the proportion of refractory castable, whole effect will be affected to a certain extent, then to tell you in the cement castable refractory in the percentage of problems:

Using cement as binder for refractory pouring material has the advantages of simple construction, wide application range and so become refractory castable most customers Pro gaze now. Refractory castable cement is the main factor to determine the initial strength of the castable refractory, so many customers that cement castable refractory in the greater proportion of the strength of the castable is better! Now I can clearly tell you: This is not right. Because if the content of cement refractory castables inside is too high, it is easy to cause the reaction in later add end mixture hardening when you need to add a certain amount of water, this will make the castable formation setting and hardening strength when certain, so we can call this kind of castable refractory for hydraulic. But there is one thing we should know is the main point to decide the strength of cement castable refractories, if the volume of cement did not add to or less will cause the strength of the castable is not ideal. But its refractory degree is not very high, so we should pay attention to the use of in room temperature when in use, and may use less cement. But really need to increase the compactness of cement or construction must be used, we can choose the refractory powder doped in to. So we in the pouring material inside when using cement must be careful not to use too much.

How to solve the problem¬-excess industry capacity of refractories

According to professional statistics, last year six refractories companies net profit amounted to 368,733,900 yuan, down 28.58%. And has announced a five-quarter net profit fell 20.54% in total. In response to this phenomenon, the

industry stakeholders believe that although China introduced the relevant policies to improve the refractory industry and disorderly development of backward production capacity problems, but excess capacity and insufficient demand in the short term is difficult to resolve the contradiction, refractories industry is still is not optimistic about the state. To solve this problem, refractory industry should develop in the following two direction.

First, improving the industry concentration the past 10 years, although China's refractory industry has achieved good results, has become the world's largest producer, consumer and exporter. But even so, the former world ranked 10 refractories business sales, there is no Chinese enterprises. Many professionals believe that the reason for this phenomenon is that the current production capacity of China's refractory industry has been transformed into a comprehensive surplus from structural surplus, market disorderly competition, low prices; order chaos by industry self-regulation is difficult to reverse. In this regard, Refractories Association drafted a "refractory industry access", was designed from the layout, process equipment, production scale, product quality, energy consumption, environmental protection aspects, utilization, safety and other enterprises to improve Refractories income threshold. This is conducive to improve the disorderly development of the industry.

Second, the increase in receivables, improve profit margins

According to the survey, in 2012 sales revenue of China's refractories business, profits have declined. 2012 slow recovery of global economic, the downstream industry downturn, lack of demand; intensified competition within the industry, resulting in some refractory product sales prices down. Many industry professionals said, because of the refractory industry and downstream enterprises are mainly non-ferrous metals such as steel and building materials industries, today's economic slow recovery, downstream firms are also facing serious overcapacity, insufficient demand phenomenon still persists, This gives the refractory industry has brought great impact, making refractories enterprises excessive competition, prices are low and thereby shrinking profit margins. Therefore, the increase of trade receivables, improve profit margins is particularly important.

Refractory industry developing trends——Cyanite

Future high-purity refractory materials will be the main and synthetic natural selection and use. Development and utilization of the "three stone" raw materials, namely andalusite, sillimanite, kyanite raw materials, can improve the microstructure and thermal properties LAS refractories.

As the "three stone" at high temperatures into the lower phase mullite and mullite expansion coefficient is small, help to improve the thermal shock resistance of the material. Andalusite in the material can be added with countless subtle diffusion thermal stress becomes void formation, making the stress to be released within the refractory, thus improving the thermal shock resistance. And sillimanite completely mullitization the temperature is higher, will help improve the high-temperature creep resistance. In addition, due to the volume expansion effect produced mullitization also accompanied by high temperature creep favorable. Development of high-quality synthetic refractory raw materials, the amount of developed countries in the use of natural raw materials reduced and the amount of high-purity synthetic raw materials is increasing, the reason is the extensive use of synthetic materials proportion of unshaped refractory materials is increasing, and the extensive use of natural raw clay brick, high alumina brick, zircon brick production is declining.

Therefore, innovation, research and development, education, management and investment, will be the key to maintaining the vitality of future refractory industry and success. Current and future years for Chinese refractories industry, is an experienced structural optimization, corporate restructuring and product structure adjustment period. China's strategy of development should be based on Chinese refractories rich natural resources, based on the development of high-performance synthetic materials and more high-performance, functional products to meet the advanced requirements of high temperature industrial development and a focus on clean steel casting and production. At the same time, you should pay attention to equipment and management, improve product quality refractory materials and the stability and reliability.

Refractory development in China

Ancient, medieval, Renaissance refractories, industrial revolution around the blast furnace, coke oven, stove refractories, refractory materials and new manufacturing processes post-modern manufacturing techniques and refractory major technological advances of modern,

as well as the future of refractories Prospects of development, refractories and high temperature technology accompanied appears roughly originated in the mid-bronze Age. China Eastern Han Dynasty has been made to burn wood and porcelain kiln sager clay refractories.

Early 20th century, the high-purity refractory, high density and ultra-high temperature product direction, while there has been complete without firing, small power consumption monolithic refractories and refractory fibers. Modern technology with the development of atomic energy, space technology, new energy technologies, high temperature, corrosion resistance, thermal shock resistance, excellent performance integrated erosion and other refractories has been applied. There are many factories in China producing refractory products. China is rich in resources, but also because the reasons for this, the major foreign investors came to China also have a go, emerge.

In China's northeast, is a supplier of refractory extremely lush areas, leading to other foreign investors lower their export prices have been questioned, which in 2003 proposed a new product for the Chinese refractories by the EU anti-dumping, limiting the product exports to the EU. 2006 China's raw material resources for the protection of a huge loss on the part of industry produced a relief rebate, thus greatly limiting refractory products exports. But this does not limit the number of foreign brands sold in large part because they have dozens or even hundreds of years of sales experience in production and market share dramatically, they also created the brand in every continent.

Several types and application of ceramic fibers

Lightweight ceramic fiber is a fibrous refractory material, the main chemical ingredient is aluminum silicate, can be classified according to their mineral composition glass fiber and polycrystalline fibers into two categories. Glass fiber is a material from the molten liquid in the cooling flow formed amorphous solid fiber;

polycrystalline fiber and more colloid injection method (or rejection wire method) into fiber, high-temperature calcinations generation.

Types and Uses.
     Ceramic fiber varieties are: ordinary aluminum silicate fiber, high alumina silicate fibers, aluminum silicate fiber (including Cr2O3, ZrO2 or B2O3), polycrystalline alumina fibers and polycrystalline mullite fiber. Form of ceramic fiber products mainly include: ceramic fiber cotton, felt, blanket, modules, paper, cloth, tape, rope, etc.

Ceramic fiber blanket (Fiber Module): use more self-blow, even the melting process is made even thrown Production spun long fibers, the fibers interwoven sided acupuncture can be directly used as a flame hot surface.Widely used in heat insulation petrochemical, metallurgy, electric power and so on.

Ceramic fiber: binder and ceramic fiber additive, after pulping, forming, curing and drying processes are made. Widely used in various heating equipment walls, roof and other parts of the backing, is a heavy refractory.

     Ceramic fiber cloth, tape: mainly used in fire doors, insulated industrial furnace insulation, heat pipes and containers.

     Ceramic fiber rope: mainly used in various industrial furnaces expansion joints, high temperature pipe insulation winding, insulation and other steel junction.

     Ceramic fiber paper: made ​​of ceramic fibers and binders, additives, after pulping, molding, curing and drying processes made, is sealed, an ideal material for insulation. Can be used for a variety of thermal furnace expansion joints, high temperature gaskets and other parts of the insulation.

Also, the ceramic fiber filter and the catalyst can be applied to a support material, packing materials and friction materials, insulating coatings, reinforcing materials.