A vertical roller mill includes a housing, a chute that supplies materials to be grinded to a center portion of the housing, a grinder that is provided below the chute and grinds the materials to be grinded, an exhaust pipe that is provided above the grinder, a transport mechanism that forms an air flow for transporting, to the exhaust pipe, grinded materials grinded by the grinder, and a flow-constricting flow path provided between the grinder and the exhaust pipe and narrows a flow path area for the air flow, in which the flow-constricting flow path is formed between a first flow-constricting ring provided in the center portion of the housing and a second flow-constricting ring provided to protrude from the housing toward the center portion of the housing.

The invention relates to a method and system for the environmental remediation of materials that are contaminated with heavy minerals, such as heavy metals. The invention finds utility in removing heavy minerals from materials such as soils, sediments, mine tailings and ores. The invention provides a means for removing heavy minerals from contaminated materials without the use of water while reducing the generation of dust. Thus, the invention provides an environmentally friendly method for the remediation of sites that are contaminated with heavy minerals.

The invention relates to a method and system for the environmental remediation of materials that are contaminated with heavy minerals, such as heavy metals. The invention finds utility in removing heavy minerals from materials such as soils, sediments, mine tailings and ores. The invention provides a means for removing heavy minerals from contaminated materials without the use of water while reducing the generation of dust. Thus, the invention provides an environmentally friendly method for the remediation of sites that are contaminated with heavy minerals.

Beneficiating particulate additives by removing contaminants or minerals that impact the quality and specific gravity of the particulate additives may be achieved via dry solids separation technologies. For example, an air classifier, an electrostatic separator, and a combination thereof may be used to produce a beneficiated particulate additive comprising less than 40% of drill solids by weight of the beneficiated particulate additive.

Beneficiating particulate additives by removing contaminants or minerals that impact the quality and specific gravity of the particulate additives may be achieved via dry solids separation technologies. For example, an air classifier, an electrostatic separator, and a combination thereof may be used to produce a beneficiated particulate additive comprising less than 40% of drill solids by weight of the beneficiated particulate additive.

A classifying wheel for a centrifugal-force air classifier where the flow pattern of the classifying air is contrary to its centrifugal direction, namely centripetal, and which is equipped with extensions fitted to the classifying wheel vanes within the flow channels which influence the flow pattern is to be executed in wear-protected design. This is achieved in that the classifying wheel has at least one reinforcing ring which has uniformly spaced hooks arranged around its periphery which fix the classifying wheel vanes to the extensions so that the outside radial edge of the classifying wheel vanes is not in contact with the reinforcing ring.

A classifying wheel for a centrifugal-force air classifier where the flow pattern of the classifying air is contrary to its centrifugal direction, namely centripetal, and which is equipped with extensions fitted to the classifying wheel vanes within the flow channels which influence the flow pattern is to be executed in wear-protected design. This is achieved in that the classifying wheel has at least one reinforcing ring which has uniformly spaced hooks arranged around its periphery which fix the classifying wheel vanes to the extensions so that the outside radial edge of the classifying wheel vanes is not in contact with the reinforcing ring.

A method for continuous aeraulic separation of particulate materials consisting of a mixture of particles that is heterogeneous in both particle size and density is provided. The method includes grinding particles of materials, generating a gas stream conveying the ground particles, first aeraulic separation on the gas stream in order to separate the particles it contains into a first fraction consisting of the coarsest particles with variable densities and a second fraction consisting of the finest particles. A second aeraulic separation is performed on the first fraction in order to separate the particles that it contains into a third fraction consisting of the coarsest and/or most dense particles and a fourth fraction consisting of the least coarse and/or the least dense particles. A re-injecting of the third fraction or the fourth fraction at the inlet of the grinding is performed while simultaneous recovery of the second fraction as well as the fourth fraction or the third fraction, respectively, as output products.

A method for continuous aeraulic separation of particulate materials consisting of a mixture of particles that is heterogeneous in both particle size and density is provided. The method includes grinding particles of materials, generating a gas stream conveying the ground particles, first aeraulic separation on the gas stream in order to separate the particles it contains into a first fraction consisting of the coarsest particles with variable densities and a second fraction consisting of the finest particles. A second aeraulic separation is performed on the first fraction in order to separate the particles that it contains into a third fraction consisting of the coarsest and/or most dense particles and a fourth fraction consisting of the least coarse and/or the least dense particles. A re-injecting of the third fraction or the fourth fraction at the inlet of the grinding is performed while simultaneous recovery of the second fraction as well as the fourth fraction or the third fraction, respectively, as output products.

Beneficiating particulate additives by removing contaminants or minerals that impact the quality and specific gravity of the particulate additives may be achieved via dry solids separation technologies. For example, an air classifier, an electrostatic separator, and a combination thereof may be used to produce a beneficiated particulate additive comprising less than 40% of drill solids by weight of the beneficiated particulate additive.