Over the past decade, the domestic steel industry continues to expand production capacity for the refractory industry to provide space for development, but at the same time users of refractory steel industry quality, ordering, payment changes also brought some problems: low bid, making
refractories manufacturers almost unprofitable; inferior new blast furnace refractories makes frequent accidents; order contract specifications agreed on refractories manufacturer's responsibility, while the responsibility of the user back section of missed appointments was not binding; new money debt risks weakening the refractory industry enthusiasm and creativity.
These issues should be how to deal with? Refractory industry had from a technical and business point of view to find solutions of the policy. Such as providing technical service work, through the service allows users to understand the key parts of the furnace refractories relationship quality and service life. I believe that the blast furnace, hot stove if you want to reduce the cost and longevity, must be of high quality refractories; while using less demanding for some refractory steels can target different requirements, grading using different grades of refractory , the implementation of competitive prices, there is no need finicky performance indicators to meet the requirements can be.
Competitive prices to ensure stable performance and promote longevity blast
General large-scale blast furnace life of 15 years to 20 years, can be considered a relatively long-lived. Ensure that they premise is to ensure the longevity of the quality of equipment and refractories.
Wuhan Iron and Steel Blast Furnace No. 5 to 16 years of life, which uses a low creep andalusite containing mullite brick. From the spectrum analysis, thanks fused corundum, sintered
corundum, mullite aggregate and fine aggregate andalusite, in line with the fine matrix component design, making use of the 16-year brick size changes very little shrinkage. The same is low creep brick, if set the price is relatively low, the manufacturer in order to maintain a certain margin, may be replaced on the material of the low-level matching materials to reduce costs. Low creep of one kinds of inferior alumina brick for analysis, the aggregate amount of alumina used, making the appearance of the cut corundum particles can be seen, but which contain quartz, it is offset by the expansion of the use of silica brick partial agonist, performance indicator has not changed much, but the use of results will be affected. Andalusite containing low creep mullite order price of 8,000 yuan / ton, and now some of the so-called low creep high alumina brick low tender price to 4,000 yuan to 5,000 yuan / ton, from raw materials derived corundum mullite Bergamo prices have more than 4000 yuan / ton, plus brick, firing, inspection and yield cost, such low prices can not guarantee quality.
Therefore, I believe, refractory product prices must be in a reasonable price range. But the question is: on the one hand, iron and steel enterprises to use the performance side of the refractory expertise is not very familiar with, so much believe in the tender and contract low-cost index; the other hand, some of the vicious competition refractory industry caused low bid prevalent, especially in the nature of successful projects total package, to suppress some of the high-quality products survive.
From the perspective of longevity used, it should be combined with refractory production process to determine the types and grades of refractory raw materials to produce products, and then focuses on analysis and use of products related to a specific performance. To ensure product performance, I believe that should be good quality and inexpensive as the premise, the only way to ensure that the manufacturer may choose appropriate materials and a reasonable ratio.
By observing the microporous carbon brick and ultramicropore carbon brick structure, in microporous carbon brick can choose massive carbon and silicon metal materials can also choose Electrically Calcined Anthracite, electrodes of graphite or other carbon material as a raw material badly. It should be noted, porous or micro-hole formation is closely related with the selection of raw materials, highly graphitized carbon material, ductile, very dense between different materials; Si content of more than 96% of silicon metal powder price reached 12,000 yuan ~ 14,000 yuan / ton, the production ultramicropore carbon brick requires high temperature, atmosphere protection, molded under pressure and heat, without the right price, it is difficult to select suitable raw materials to ensure product quality. In recent years, some blast frequent accidents is one of the reasons which led to too much emphasis on low bid refractory products of inferior quality.
Distinction between different parts of the selection so that the overall life balance
Metallurgical furnaces in the steel industry, the use of different parts, subjected to different environments, so the refractory requirements are also different. If not treated differently, may cause severe localized damage resulting overall in the repair or overhaul. Such as blast furnace main ditch, erosion is the most serious part of the slag line and slag dam site. Early primary trough castable only one grade, SiC content is generally 11wt% ~ 13wt% (weight percent). 3200m3 blast through the main groove again without patching the amount of iron in the 80,000 tons - 100,000 tons; using SiC content in 20wt% ~ 30wt% of the slag line castable castable with integrated wire masonry, once casted, with preformed The slag dam, 3200m3 blast through the main groove again without patching the amount of iron can be increased to 120,000 tons to 18 tons. Another example pellets kiln refractories, kiln barrel portion to abrasion, impact, peel the most serious, if you use a material masonry, may Yaotou life span of only six months to eight months, the other cylinder parts of the life expectancy of two years, therefore, the shortest life parts need to be replaced, it will affect the overall usefulness.
However, compared to the refractory masonry process and quality improvement, iron and steel enterprise users are more concerned about the cost and whether it will affect the production process. From the point of view refractory iron trough: 97% to 98% of the content of silicon carbide price reached 5,700 yuan ~ 6600 yuan / ton, dense corundum is 5000 yuan to 5500 yuan / ton, plus the cost of the matrix powder, high-grade casting material cost may be at 5500 yuan to 6500 yuan / ton, so the key parts of the use of high-grade materials, with parts in general, the use of suitable refractory refractory manufacturer can guarantee profitable, but also contribute to the achievement of economic mills procurement. In fact, the main iron blast furnace refractories ditch change precisely because of tons of iron under contract measures the results of technological progress (tons of iron contract provides for one ton of iron consumed Refractories amount, prompting refractory supplier active in quality assurance case, a reasonable match). Large-scale overhaul of the current rotary kiln pellet life is 2 years, if the realization of t ball refractory consumption contracted, kiln castable may truly competitive prices, refractory masonry achieve integrated sub-parts and maintenance, up to 3 years to 5 years of overhaul life is possible.
In refractory technology development process, once the high-temperature firing, high purity raw materials, high pressure forming as a technology development direction. With the increase in product cost pressures, refractories manufacturers increased the low-end raw materials, research and the use of recycled material, but from the perspective of the scene, the harsh conditions of use of the material bound to put forward higher requirements. Therefore, the use of different grades of materials integrated masonry, composite used to achieve the best balance life is the pursuit of refractory technology direction. High temperature firing, high purity materials, hydroforming can get excellent performance, it can be used in key parts of the overall costs can still be reduced. For example using a high temperature firing slide brick inner zirconia is a typical example, expensive materials to withstand molten zirconia erosion damage, and other composite materials as the slide body material, increasing the frequency of use, comprehensive cost down.
For the different grades of material to provide the appropriate use of space
As the refractory industry profit margins shrinking, manufacturers began to seek alternative raw material point of view, as far as possible to reduce costs. The typical case is the steelmaking tundish coating.
Tundish coating if the price of 1800 yuan to 2000 yuan / ton, the use of MT-2 ~ MT-4 standard paint, MgO content of 90% to 97% of the magnesia price is 950 ~ 1700 yuan / ton, the production enterprises for meager profits; if the price to 1,500 yuan / ton or less, it is unprofitable. For this reason, many manufacturers use the price is only 450 yuan to 500 yuan / ton to do some forsterite alternative raw materials production forsterite coating, the effect can also be used to meet the requirements. Such as by high MgO content standards assessment, the product failed, such as by coating MT-1, MT-5 index, forsterite coating composition may meet the requirements.
The key question is magnesia coating may affect the quality of certain types of steel. For example studies have shown that: with respect to the low alkalinity magnesia spray paint and cover agent, calcium with magnesium and calcium spray paint covering agent, the molten steel ≥ 5μm removal of inclusions increased by 82.2% to 83.4%, ≥ 0.55 μm inclusions removal by a 79.1% increase to 83.0%; total oxygen content of molten steel can be reduced from 8% to 14%, reducing the total nitrogen content of molten steel from 8% to 16%. But for most users, forsterite coating still meet their requirements.
Thus, it should encourage the use of different conditions using a suitable refractory material, in order to expand the use of different grades of refractory space. Refractories technology development has an iterative process, such as dolomite lining - carbonaceous lining - carbon bag lining the change process; Similarly, the steel industry, there are some techniques repeatedly, such as previously used for steelmaking slag lime Now in order to reduce the cost of steel, a few steel slag with limestone also achieved success. Refractory practitioners only time tracking the user's requirements, and carry out technological change, will it be possible at the lowest cost to meet the user's requirements.
From low creep high alumina bricks for blast furnace carbon brick, castable kiln pellet analysis, such as: to ensure a reasonable purchase price producers may choose only quality raw materials to ensure product quality. For refractory practitioners, using square steel companies must communicate to the high cost of technology and products to ensure the longevity of the blast furnace system, stable use. For such as blast furnace ditch, life is not too long rotary kiln and other high-temperature equipment, key parts of the use of high quality materials to meet the harsh conditions of use desired, by using different grades of materials integrated masonry, composite used to achieve the best balance life, in order to reduce costs and reduce costs.
The author believes that infinitely depress refractory purchase price, will ultimately harm the development of the steel industry. Press tons of iron, tons of steel, tons of refractory consumption calculation which gives the ball a suitable refractory refractory prices favor technological progress, but also conducive to steel mills in the effectiveness and quality assurance using the case to be more economical procurement costs. Generally lower profit margins in the steel industry under the premise of the refractory industry must proactively improve the technical content, changing the mode of operation, through the money to pay for the goods, technology UNPROFOR, improve service quality, etc., to ensure smooth production of steel users, and ultimately achieve mutual benefit and win-win results.
