Abstract: In grinding of a raw material by a vertical roller mill, highly-efficient grinding is performed irrespective of the type of the raw material, and the life of the mill roller is extended. In order to achieve these, in a grinding roller used in a vertical roller mill, an outer circumferential surface of the roller as a grinding surface is divided into a main grinding surface that mainly performs pulverizing and a grinding surface other than the main grinding surface. The main grinding surface is made smooth, and the grinding surface other than the main grinding surface is a raw material transfer surface in which slit grooves inclined at 90 degrees or an angle exceeding 45 degrees relative to a roller circumferential direction or screw grooves inclined at 45 degrees or smaller relative to the roller circumferential direction are formed.

Abstract: In grinding of a raw material by a vertical roller mill, highly-efficient grinding is performed irrespective of the type of the raw material, and the life of the mill roller is extended. In order to achieve these, in a grinding roller used in a vertical roller mill, an outer circumferential surface of the roller as a grinding surface is divided into a main grinding surface that mainly performs pulverizing and a grinding surface other than the main grinding surface. The main grinding surface is made smooth, and the grinding surface other than the main grinding surface is a raw material transfer surface in which slit grooves inclined at 90 degrees or an angle exceeding 45 degrees relative to a roller circumferential direction or screw grooves inclined at 45 degrees or smaller relative to the roller circumferential direction are formed.

Abstract: In grinding of a raw material by a vertical roller mill, highly-efficient grinding is performed irrespective of the type of the raw material, and the life of the mill roller is extended. In order to achieve these, in a grinding roller used in a vertical roller mill, an outer circumferential surface of the roller as a grinding surface is divided into a main grinding surface that mainly performs pulverizing and a grinding surface other than the main grinding surface. The main grinding surface is made smooth, and the grinding surface other than the main grinding surface is a raw material transfer surface in which slit grooves inclined at 90 degrees or an angle exceeding 45 degrees relative to a roller circumferential direction or screw grooves inclined at 45 degrees or smaller relative to the roller circumferential direction are formed.

Abstract: In grinding of a raw material by a vertical roller mill, highly-efficient grinding is performed irrespective of the type of the raw material, and the life of the mill roller is extended. In order to achieve these, in a grinding roller used in a vertical roller mill, an outer circumferential surface of the roller as a grinding surface is divided into a main grinding surface that mainly performs pulverizing and a grinding surface other than the main grinding surface. The main grinding surface is made smooth, and the grinding surface other than the main grinding surface is a raw material transfer surface in which slit grooves inclined at 90 degrees or an angle exceeding 45 degrees relative to a roller circumferential direction or screw grooves inclined at 45 degrees or smaller relative to the roller circumferential direction are formed.

Abstract: To provide a high-performance, inexpensive low C-high Si-high Cr—B—Nb type iron-based corrosion-resistant and wear-resistant alloy that is extremely superior in corrosion resistance and wear resistance to 304 stainless steel, high-chromium cast iron and high carbon-high chromium cast-iron-type materials, has a high corrosion-resistant property that would never be obtained from a high carbon-high chromium carbide precipitation-type iron-based wear-resistant alloy and at the same time, a wear-resistant property that is superior to these metals, and further hardly causes brittle peeling that is inherent to high Si—containing steel. This alloy contains, all percentages by weight, C: 0.5 to 2.5% by weight, Si: 2.5 to 4.5%, Mn: 0 to 10% or less, Cr: 15% to 31%, Ni: 0 to 16%, Cu: 7% or less, Mo: 10% or less, B: 0.5% to 3.5%, and 0?Nb+V?8%, and in this structure, within a range of 15% Cr?Cr<27%, (Si×B)?2014/Cr2+0.083Cr+1.05 is satisfied, within a range of 27%?Cr?31%, 1.25%?(Si×B) 6.

Abstract: The crushing surfaces (a) or (b) are composed of two types of blocks 1 and 2 which differ in wear resistance and which are arranged alternately.

Abstract: An articulate bent pipe for transport of powder and slurry is composed of a plurality of sector shaped nodular pipes having a wear resistant pipe lining applied on the interior thereof and packing means positioned between each nodular pipe. The nodular pipes are secured together to form the bent pipe. Steps are formed between axial edges of adjacent inner surfaces of the linings for upstream nodular pipes.