The Development of Refractory Ramming Mass

 The ramming mass refers to ramming (manual or mechanical) method of construction, and hardened in the heating effect is higher than normal temperature under the unshaped refractory materials. 

By refractory aggregate, with certain gradation of powder, binder, additive water or other liquid after mixing.According to the material classification with high alumina, clay, magnesite, dolomite, zirconium and silicon carbide carbon refractory ramming material.

Refractory Ramming Mass Function: 

ramming material is made of silicon carbide, graphite, electric calcined anthracite as raw material, mixed with a variety of ultra-fine powder additives, fused cement or composite resin as the binder made of bulk cement.To fill the gap or stack cooling equipment and masonry masonry filler. 

Refractory Ramming Mass Types: 

The leveling layer with acidic, neutral and alkaline ramming material widely used in intermediate frequency coreless furnace core induction furnace, as if furnace ramming material used for melting aluminum and its alloys, melting of copper, brass, copper and bronze and copper alloy etc.

The carbon ramming mass as an example: according to the different type of blast furnace and the material design requirements of different carbon ramming material is mainly used for blast furnace carbon brick and bottom sealing gaps between plates and carbon bricks and the cooling wall, and filling the furnace bottom water cooling tube over the central line of the leveling and cooling wall, all parts are required by ramming carbon ramming after ramming mass has a certain strength and density, and filled every corner of a small gap, to achieve no leakage of hot metal and gas demand,Classification and construction: all ceramic ramming material consisting of material is divided into: clay, high alumina, carbon, magnesium and dolomite.

Refractory Ramming Mass Advantages:

High erosion resistance.

High bonding strength.

Short lead time.

Free engineering services to guarantee service life.

Ramming mass is used in various industrial places for manufacturing of many refractory materials. It is prepared with great precision using modern techniques and quality materials. Corrosion resistant with a high level of thermal stability, it offers maximum output and last longer. It can be used in lining of iron, lining the trough of blast furnaces, lining of induction furnaces, used as insulation for rapid drying. Also, available in a premixed form allows lesser wastage, consistent and longer lining and patching life.  Ramming mass is prepared using quality components and other raw material as per the industrial set standards and norms with great precision. The even and regular granule of the powder are appreciated by the clientele.

Neutral Ramming Mass VS Silica Linings

Silica ramming mass can safely be used up to an operating temperature of 1600 deg C. Since it expands very little, it is superior to both alumina and magnesia refractories to resist thermal shocks. Though silica lining has good endurance against thermal shock, it has poor resistance against steelmaking slags. Temperature control is very necessary for a satisfactory lining life.

The addition of right quantity of boric acid is very important for optimum life of lining. 

The quantity depends upon (i) temperature of liquid metal bath, (ii) chemical composition of quartzite mass, and (iii) thickness of crucible wall. 

Silica linings are the conventional lining solution widely used in both ferrous and non-ferrous foundries. Mainly made of crystalline silica and commonly known as acidic ramming mass, the typical binding agents that aid in the sintering of silica linings are boron-based. This refractory lining exhibits mainly low thermal expansion and have excellent thermal shock resistance. 

Neutral ramming mass are a unique, chemically neutral foundry solution that form joint-less linings. The in-situ spinels synthesise at high temperatures inside the refractory lining, creating a unique 3-layer structure. The outermost layer in contact with the molten metal is a hard, sintered surface, followed by an intermediate fritted layer. The innermost layer stays in a powdery form.

Neutral ramming mass

Lining wear and the causes of wear

The lining life of induction furnace lined with silica ramming mass depends upon the lining practice and operating practice of the furnace besides quality of the silica ramming mass. It is quite common to get inconsistent lining life of the furnace. There are cases when sudden failure of lining takes place. 

The main factors which affects the lining life of the induction furnace are 

(i) incorrect granulometry of the ramming mass, 

(ii) non-uniform distribution of the binding agent, 

(iii) superheating of the metal bath in the furnace, 

(iv) penetration of metal, 

(v) minimum slag free metal resulting in minimum erosion at slag line, 

(vi) loss of refractory powder, and (vii) topping/lining interface cracking

For the proper failure analysis in case of pre-mature failure of the refractory lining, it is important that proper records about output, working temperature, and other parameters are maintained. These records not only help in finding the cause of failure but also help in the continuous performance of the lining life.

Article Source: The Development of Refractory Ramming Mass
Company name: Henan Changxing Refractory Materials Co.,Ltd
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