The pellet shaft furnace belongs to metallurgical equipment and is used for roasting metallurgical pellets. The structure of pellet shaft furnace is relatively simple, the temperature in the shaft furnace is uniform, the roasting efficiency is high, the output is high, the quality is even, and so on.
The production process of pellet shaft furnace is composed of six links: batching, drying, moistening, pelletizing, roasting and cooling. Firstly, the pelletizing is carried out on the disk pelletizing machine. The mineral powder and water act on the ball to form the ball core. The ball core rolls continuously in the material, adheres to the material, and the ball becomes bigger and bigger, more and more compact, forming the ball with enough strength.

After the qualified raw pellets are generated, they should be sent to the shaft furnace of the pellet for roasting. After drying and preheating, they will be roasted in the oxidation atmosphere. Roasting is the main stage of pellet consolidation. After roasting, they will be sent to the belt cooler by the chain board machine for cooling, and then they will be sent to the ripening field for stacking to complete the pellet production.

Under normal circumstances, the pellet shaft furnace has certain requirements for the mineral powder, which needs to use the mineral powder with good hydrophilicity, fine particle size, specific surface area and good angle connection conditions. According to the user's requirements, the grade of ordinary magnetite concentrate is required to be more than 63, the fineness of mineral powder is more than 200 mesh and 85%, and the water content of bentonite mixture is controlled between 6% and 7%.
      Shaft furnace wind guide wear-resistant brick is made of bauxite clinker, mullite, kyanite, zircon sand and binder, which are first granulated and powdered, then mixed in a certain proportion, and then pressed into shape. It is fired at high temperature to produce products with good resistance to high temperature, erosion and erosion. It is mainly used for the wind guide wall of the pelletizing shaft furnace in the iron and steel plant.
Anchor brick, also known as hanging brick, is made of high-quality raw materials by mechanical pressing or pouring and sintering at high temperature.

Anchor brick plays an important role in building the straight wall, which can improve the integrity of the straight wall.

The alumina content of anchor brick is more than 55%, the alumina content of high-quality anchor brick can reach 75%, the load softening temperature of this kind of brick can reach 1550 ℃, which is a good refractory brick product. But in general, the alumina content of 55% is selected, because the flexibility of the anchor brick with 55% is better.

In addition, it should be noted that the anchor brick is used to anchor the refractory castable, and the properties of the anchor brick should be consistent with the castable material, expansion and contraction, so as to form a close combination with the castable and extend the life of the furnace lining.

Product usage:

1. The arrangement of anchor bricks shall be determined according to the change range and frequency of temperature and the size of the area of the straight wall, generally not less than 6 pieces / m2.

2. Before masonry, the anchor brick must be checked carefully. If there is any crack affecting the overall strength of the anchor brick at the anchor hole, the anchor brick cannot be used, and should be discarded resolutely.

3. When the masonry is close to the anchor brick position, it is necessary to row the bricks in advance to determine the exact position of the anchor brick. It is to thoroughly clean the welding part of the metal shell with a wire brush, use the welding rod suitable for the welding parts, and firmly weld the anchor pipe.

4. After the completion of the anchor brick masonry, insert the anchor hook, and fill the air attack with fire-resistant fiber felt and plug tightly to form a certain protection for the anchor.

The anchor brick consists of a column composed of a hanging end and an anchor solid, which is provided with an interval division groove on the surface of the anchor solid. At least one surface of the anchor solid is provided with a bar along the length direction. After the bar is provided, the tensile and flexural strength of the anchor solid is significantly improved due to the reinforcement and traction of the bar, and the stress generated at the groove is blocked at the bar and cannot be transmitted continuously, so The anchor brick of this kind of structure is not easy to break.
       Steel fiber reinforced castable is made up of super alumina clinker as aggregate, fine alumina clinker and corundum fine powder as matrix, ultra-fine powder and other composite materials as binder and additive, plus stainless steel heat-resistant fiber. At the same time, due to the addition of steel fiber, the overall strength of furnace wall is greatly enhanced after the material is poured.

Production process:

In fact, the use method is basically the same as that of concrete. After the selected formula and raw materials are evenly stirred and processed, they can be compacted with a vibrating rod, and then cured and heated. Because of the particularity of the use part of the unshaped castable, the construction quality of the castable needs to be guaranteed according to the different site conditions.

On the basis of using high alumina clinker as aggregate and powder for its important part, adding appropriate steel fiber casting reinforced castable has the characteristics of high strength, good toughness, good thermal shock stability, strong peeling resistance and wear resistance. It is used in the parts where the temperature step changes easily lead to the damage of furnace wall.

Application of steel fiber reinforced castable: mainly used for lining of rotary kiln

Low temperature section of kiln body: steel fiber reinforced corundum mullite castable 2.5. High temperature section of kiln body: anti caking ring castable 2.6.

Kiln head shell: steel fiber reinforced corundum mullite castable 2.7.

Clay refractory brick for shaft furnace is a kind of clay brick used for lining blast furnace. Clay firebrick for blast furnace is used for throat, shaft, hearth, bottom and shaft of small blast furnace lining.

Clay refractory brick for shaft furnace requires high fire resistance at room temperature and can resist long-term operation wear of furnace charge; small volume shrinkage under high temperature and long-term operation is conducive to the integrity of furnace lining; low apparent porosity and Fe2O3. Low content, reduce carbon deposition in pores, avoid expansion and damage of firebrick in the use process; low melting point formation is less. Clay firebrick for blast furnace has better performance than common clay brick.

        As the basic material of high temperature industry, high alumina refractory brick is widely used in steel, building materials, petrochemical, nonferrous and other industries, and it is a kind of refractory brick products with a large amount of use. High alumina brick series products are very popular in the market. Whether it is the standard brick type of national standard series or the customized special-shaped brick, the refractory has rich production experience and mature technology.

Analysis of the advantages of high alumina brick for shaft furnace

The appearance of air guide wall and drying bed has promoted the development of pellet shaft furnace in China. However, the low service life of the air guide wall has been perplexing the development of shaft furnace pellet production for many years. The reasons for the low service life of the air guide wall are as follows: first, the brick body of the air guide wall is easy to be damaged and collapsed; second, the water-cooled joist of the air guide wall is easy to be deformed, bent down (or "collapsed waist") and worn, resulting in water leakage and brick wall collapse.

There are two kinds of refractory materials for wind guide wall of shaft furnace, namely, aluminum zirconium and sillimanite mullite, with service life of more than 1 year and 3 years respectively. Its main features are:

(1) On the basis of Al Si system materials, adding appropriate compound additives, it can form stable zirconium mullite phase or sillimanite phase at high temperature, so it has a good effect of high temperature resistance and erosion resistance.

(2) The combined structure greatly reduces the brick joints of the air guide wall, and the overall performance of the masonry is good and the service life is long.

(3) Our company's professional furnace construction team can provide users with air guide wall masonry services to ensure the quality of air guide wall masonry.

(4) The company provides baking curve for users, which can avoid and reduce the impact of baking operation on refractory quality.