Systems and methods for generation of lime hydrate compounds and particularly highly reactive hydrated lime (HRH) with a reduced resistivity through the inclusion of a sodium compound generally in the slaking water used in generating the lime hydrate or HRH. The compound may then be used in systems which include a Electrostatic Precipitator (ESP) for SO.sub.2 mitigation without many of the associated problems in ESP performance.

Systems and methods for generation of lime hydrate compounds and particularly highly reactive hydrated lime (HRH) with a reduced resistivity through the inclusion of a sodium compound generally in the slaking water used in generating the lime hydrate or HRH. The compound may then be used in systems which include a Electrostatic Precipitator (ESP) for SO.sub.2 mitigation without many of the associated problems in ESP performance.

A planetary roller mill for processing a feed material includes a vessel with a grinding ring having an opening therethrough and a first area. The grinding ring is in sealing engagement with the inside surface of the vessel assembly. At least two non-circular support plates are secured to a rotatable shaft. Each plate has an axially facing surface. A plurality of rollers rotatably are mounted to and positioned between the two support plates. Each of the plurality of rollers are in grinding communication with the grinding surface. The planetary roller mill includes an air supply system having an outlet in communication with the opening in the grinding ring. Areas of the two support plates are of magnitudes which configure a flow area through the opening of at least 30 percent of the first area to provide a predetermined quantity of heated air to remove moisture from the feed material in the grinding assembly.

A planetary roller mill for processing a feed material includes a vessel with a grinding ring having an opening therethrough and a first area. The grinding ring is in sealing engagement with the inside surface of the vessel assembly. At least two non-circular support plates are secured to a rotatable shaft. Each plate has an axially facing surface. A plurality of rollers rotatably are mounted to and positioned between the two support plates. Each of the plurality of rollers are in grinding communication with the grinding surface. The planetary roller mill includes an air supply system having an outlet in communication with the opening in the grinding ring. Areas of the two support plates are of magnitudes which configure a flow area through the opening of at least 30 percent of the first area to provide a predetermined quantity of heated air to remove moisture from the feed material in the grinding assembly.

The invention relates to a process for the wet milling of slag, wherein more than 100 kWh of milling energy are introduced per metric ton of slag and the weight ratio of slag to water is 0.05-4:1 and from 0.005 to 2% by weight, based on the slag, of a milling auxiliary which comprises at least one compound selected from the group consisting of polycarboxylate ether, phosphated polycondensation product, lignosulfonate, melamine-formaldehyde sulfonate, naphthalene-formaldehyde sulfonate, monoglycols, diglycols, triglycols and polyglycols, polyalcohols, alkanolamine, amino acids, sugar, molasses and curing accelerators based on calcium silicate hydrate is added to the material being milled before or during the milling.

The invention relates to a process for the wet milling of slag, wherein more than 100 kWh of milling energy are introduced per metric ton of slag and the weight ratio of slag to water is 0.05-4:1 and from 0.005 to 2% by weight, based on the slag, of a milling auxiliary which comprises at least one compound selected from the group consisting of polycarboxylate ether, phosphated polycondensation product, lignosulfonate, melamine-formaldehyde sulfonate, naphthalene-formaldehyde sulfonate, monoglycols, diglycols, triglycols and polyglycols, polyalcohols, alkanolamine, amino acids, sugar, molasses and curing accelerators based on calcium silicate hydrate is added to the material being milled before or during the milling.

The present invention pertains to the discovery that short chain aliphatic fatty acids, such as potassium sorbate, can be used in liquid-additive grinding compositions in the amount of at least 10%, more preferably at least 20%, and most preferably at least 30%, to mill carbonate materials into smaller particle size. The carbonate material can optionally be combined with another inorganic material in the grinding operation, such as limestone, lime, dolomites, talc, titanium dioxide, alumina, and kaolin, ceramics, and cement clinker. The use of the particularly described grinding additive composition are food-grade or food-contact approved, and are believed by the present inventors to resist the humectant behavior of the resultant ground particles which could in herently otherwise decrease efficiency of the particulate grinding process.

The present invention pertains to the discovery that short chain aliphatic fatty acids, such as potassium sorbate, can be used in liquid-additive grinding compositions in the amount of at least 10%, more preferably at least 20%, and most preferably at least 30%, to mill carbonate materials into smaller particle size. The carbonate material can optionally be combined with another inorganic material in the grinding operation, such as limestone, lime, dolomites, talc, titanium dioxide, alumina, and kaolin, ceramics, and cement clinker. The use of the particularly described grinding additive composition are food-grade or food-contact approved, and are believed by the present inventors to resist the humectant behavior of the resultant ground particles which could in herently otherwise decrease efficiency of the particulate grinding process.

Provided are processes of preventing or eliminating caking of particulate materials during milling operations. Processes include the addition of an anti-caking additive such as a rosin, abietic acid, fatty acid, or derivative of any of the foregoing to a mill prior to or along with a particulate chemical, and milling the combination. The addition of the anti-caking additive prevents or reduces the amount of caking observed thereby increasing yields and maintaining or enhancing the resulting properties of the milled product.

An example method of preparing spherical composite powders is provided. The method includes introducing one or more starting material powders into an agitation mill. The method includes introducing a process control agent into the agitation mill, the process control agent including at least two immiscible liquids. The method includes agitating and milling the one or more starting material powders and the process control agent with the agitation mill to produce substantially spherical composite powders.