Liaoning Haicheng Xinyue Refractories Co., Ltd.
Mobile phone: +86-15041737767 +86-13322303666
Address: East Pai Lou Industrial Park, Pai Lou Town, Haicheng, Liaoning.
The refractory ramming material is composed of reasonable graded refractory aggregate, powder and binder, ramming material admixture and so on. It is an unshaped refractory material constructed by manual or mechanical ramming method. For example, it can be used as the lining of induction furnace, heating furnace, soaking furnace, as well as the filler of converter lining, aluminum reduction cell and so on.
The refractory ramming material can be made up of refractory aggregate and powder material for ramming materials according to the need. At the same time, according to the refractory aggregate material and the use of requirements to select the appropriate binder, some ramming materials do not need binder but only a small amount of flux to promote its sintering. In the acid ramming materials, sodium silicate, ethyl silicate and silica gel are commonly used as binding agents. Alkaline ramming materials use aqueous solutions such as magnesium chloride and sulfate as well as phosphates and their polymers as binders. Higher carbon-containing organic compounds and temporary binders that form carbon bonds at high temperatures are often used. Glauber's salt is used as binder for chrome ramming. Phosphoric acid and aluminum phosphate, chloride, sulfate and other inorganic substances are commonly used as binders for high alumina and corundum ramming materials. When phosphoric acid is selected as binder, it is difficult to construct because phosphoric acid reacts with active alumina in ramming material and forms aluminium orthophosphate precipitate which is insoluble in water. Therefore, in order to prolong the storage period of ramming materials, proper preservatives must be added to prevent or delay the occurrence of coagulation hardening. Oxalic acid is usually used as a preservative. Carboniferous ramming material mainly uses the binder which forms carbon bond, and uses asphalt tar or resin as binder to form carbon bond. It can prevent molten metal from wetting, improve corrosion resistance and thermal shock resistance, and prevent dolomite from hydration in dolomite ramming material.
The refractory ramming material is mainly used in the direct contact with the melt, requiring that the refractory must have good volume stability, compactness and corrosion resistance, so generally choose high temperature firing or fusing raw materials. The maximum particle size of ramming material is related to the use part and the construction method. The critical particle size is 8mm. Most ramming materials have low strength at room temperature before sintering, and some have low strength at medium temperature. Good bonding can be achieved only when the ramming materials are sintered or the carbonaceous compounds in the binder are coked. The refractoriness and corrosion resistance of ramming materials can be obtained by selecting high quality raw materials, adjusting reasonable mixing ratio and careful construction. In addition to high stability and corrosion resistance at high temperature, the service life of ramming material depends to a great extent on the baking before use or the sintering quality of the first use. If the heating surface is sintered as a whole without cr