Method and apparatus for grinding particulate solids

A method of grinding solids comprising the steps of:

• A. providing a batch of particulate solids to be ground suspended in a liquid continuum;
• B. forming a comminuting means by establishing a bed of agitated grinding elements in a comminuting vessel;
• C. repeatedly circulating the liquid continuum containing suspended solids sequentially through pump means and the comminuting means at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• D. grinding said solids in the comminuting means as the liquid continuum steadily passes through the comminuting means;
• and
• E. continuing steps B through D until the solids in the batch are reduced to desired particle size.

A method of grinding solids comprising the steps of:

• A. providing a batch of particulate solids to be ground suspended in a liquid continuum in a retaining chamber;
• B. circulating the liquid continuum containing solids from the retaining chamber into a comminuting means at one end thereof at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• C. grinding said solids in the comminuting means as the liquid continuum containing solids steadily passes through the comminuting means;
• D. discharging the liquid continuum containing suspended solids from the comminuting means at an end substantially opposite the circulation to the means into the retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• and
• E. simultaneously continuing steps B through D until the solids in the batch are reduced to desired particle size.

A method of grinding solids comprising the steps of:

• A. providing a batch of particulate solids to be ground suspended in a liquid continuum in a retaining chamber;
• B. forming a comminuting means by establishing a bed of agitated grinding elements in a comminuting vessel;
• C. circulating the liquid continuum containing suspended solids from the retaining chamber into the comminuting means at one end thereof at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• D. grinding said solids in the comminuting means as the liquid continuum containing solids steadily passes through the comminuting means;
• E. discharging the liquid continuum containing solids from the comminuting means at an end substantially opposite the circulation to the means into the retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• and
• F. simultaneously continuing steps B through E until the solids in the batch are reduced to desired particle size.

A method of grinding solids comprising the steps of:

• A. providing a batch of particulate solids to be ground suspended in a liquid continuum in a first retaining chamber;
• B. circulating the liquid continuum containing suspended solids from the first retaining chamber into a comminuting means at one end thereof at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• C. grinding said solids in the comminuting means as the circulated liquid continuum containing solids steadily passes through the comminuting means;
• D. discharging the liquid continuum containing suspended solids from the comminuting means at an end substantially opposite the circulation to the comminuting means into a second retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour until a batch is provided in the second retaining chamber;
• E. thereafter recirculating the liquid continuum containing solids from the second retaining chamber into the comminuting means at one end thereof at a rate of at least about 30 volumes of the liquid continuum containing solids in the comminuting means per hour;
• F. grinding said solids in the comminuting means as the recirculated liquid continuum steadily passes through the comminuting means;
• G. discharging the liquid continuum containing solids from the comminuting means at an end substantially opposite the recirculation to the means into a third retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour until a batch is provided in the third retaining chamber;
• and
• H. repeating steps B through G until the solids in the batch are reduced to desired particle size.

A method of grinding solids comprising the steps of:

• A. providing a batch of particulate solids to be ground suspended in a liquid continuum in a first retaining chamber;
• B. forming a comminuting means by establishing a bed of agitated grinding elements in a comminuting vessel;
• C. circulating the liquid continuum containing suspended solids from the first retaining chamber into the comminuting means at one end thereof at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• D. grinding said solids in the comminuting means as the circulated liquid continuum containing solids steadily passes through the comminuting means;
• E. discharging the liquid continuum containing suspended solids from the comminuting means at an end substantially opposite the circulation to the comminuting means into a second retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour until a batch is provided in the second retaining chamber;
• F. thereafter recirculating the liquid continuum containing solids from the second retaining chamber into the comminuting means at one end thereof at a rate of at least about 30 volumes of the liquid continuum containing solids in the comminuting means per hour;
• G. grinding said solids in the comminuting means as the recirculated liquid continuum steadily passes through the comminuting means;
• H. discharging the liquid continuum containing solids from the comminuting means at an end substantially opposite the recirculation to the means into a third retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour until a batch is provided in the third retaining chamber;
• and
• I. repeating steps B through H until the solids in the batch are reduced to desired particle size.

Apparatus for comminuting particulate solids contained in a liquid continuum comprising:

• A. an agitated-media comminuting means having (1) a substantially cylindrical comminuting vessel with an axial axis, (2) a rotatable agitator with a shaft disposed substantially along said axis and with protuberances extending outwardly from said axis to near cylindrical walls of said comminuting vessel, (3) a mass of grinding elements disposed in said comminuting vessel to overlie at least some of said protuberances, (4) means for rotating said agitator to cause said mass of grinding elements to have an increased apparent volume, and (5) inlet and outlet openings for respectively permitting liquid carrying particulate solids to be ground to enter said comminuting vessel, pass through said agitated grinding elements, and thereafter exit said comminuting vessel;
• B. pump means for causing repeated flow of at least 30 volumes of liquid containing particulate solids in the comminuting means per hour successively through said comminuting means;
• and
• C. conducting means for circulating the liquid containing particulate solids from one end portion of the comminuting vessel through the pump means and back to end portions of the comminuting vessel substantially opposite the end portion where the liquid containing particulate solids exited the comminuting vessel.

Apparatus for comminuting particulate solids contained in a liquid continuum comprising:

• A. an agitated-media comminuting means having (1) a substantially cylindrical comminuting vessel with an axial axis, (2) a rotatable agitator with a shaft disposed substantially along said axis and with protuberances extending outwardly from said axis to near cylindrical walls of said comminuting vessel, (3) a mass of grinding elements disposed in said comminuting vessel to overlie at least some of said protuberances, (4) means for rotating said agitator to cause said mass of grinding elements to have an increased apparent volume, and (5) inlet and outlet openings for respectively permitting liquid carrying particulate solids to be ground to enter said comminuting vessel, pass through said agitated grinding elements, and thereafter exit said comminuting vessel;
• B. a retaining portion integral with the comminuting vessel adjacent the comminuting means separated from the comminuting means by a retaining screen for retaining the grinding elements while permitting passage of the liquid containing particulate solids from the comminuting means into the retaining portion;
• C. pump means for causing repeated flow of at least 30 volumes of liquid containing particulate solids in the comminuting means per hour successively through said comminuting means;
• and
• D. conducting means for circulating the liquid containing particulate solids from one end portion of the comminuting vessel through the pump means and back to end portions of the comminuting vessel substantially opposite the end portion where the liquid containing particulate solids exited the comminuting vessel.

A particulate solid material having relatively small particle size and substantial particle size uniformity prepared by:

• A. providing a batch of particulate solids to be produced suspended in a liquid continuum;
• B. circulating the liquid continuum containing suspended solids repeatedly through a comminuting means at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• C. grinding said solids in the comminuting means by passing the liquid continuum containing solids through a bed of agitated grinding elements as the liquid continuum containing solids steadily flows through the comminuting means;
• and
• D. simultaneously continuing steps B and C until the solids in the batch are reduced to desired particle size.

A particulate material having substantially greater particle size uniformity prepared by:

• A. providing a batch of particulate solids to be produced suspended in a liquid continuum in a first retaining chamber;
• B. circulating the liquid continuum containing suspended solids from the first retaining chamber into a comminuting means at one end thereof at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• C. grinding said solids in the comminuting means by passing the liquid continuum containing solids through a bed of agitated grinding elements as the circulated liquid continuum steadily flows through the comminuting means;
• D. discharging the liquid continuum containing solids from the comminuting means at an end substantially opposite the circulation to the means into a second retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour until a batch is provided in the second retaining chamber;
• E. thereafter recirculating the liquid continuum containing suspended solids from the second retaining chamber into the comminuting means at one end thereof at a rate of at least about 30 volumes of the liquid continuum containing solids in the comminuting means per hour;
• F. grinding said solids in the comminuting means as in step C as the recirculated liquid continuum steadily flows through the comminuting means;
• G. discharging the liquid continuum containing solids from the comminuting means at an end substantially opposite the recirculation to the comminuting means into the first retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour until a batch is again provided in the first retaining chamber;
• and
• H. repeating steps B through G until the solids in the batch are reduced to desired particle size.

A particulate ferromagnetic material having increased magnetic capabilities prepared by:

• A. providing a batch of particulate solids to be produced suspended in a liquid continuum in a retaining chamber;
• B. circulating the liquid continuum containing suspended solids repeatedly through a comminuting means at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• C. grinding said solids in the comminuting means by passing the liquid continuum containing solids through a bed of agitated grinding elements as the liquid continuum containing solids steadily flows through the comminuting means;
• and
• D. simultaneously continuing steps B through C until the solids in the batch are reduced to desired particle size.

A particulate ferromagnetic material having increased magnetic capabilities prepared by:

• A. providing a batch of particulate solids to be produced suspended in a liquid continuum in a first retaining tank;
• B. circulating the liquid continuum containing suspended solids from the first retaining chamber into a comminuting means at one end thereof at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour;
• C. grinding said solids in the comminuting means by passing the liquid continuum containing solids through a bed of agitated grinding elements as the circulated liquid continuum steadily passes through the comminuting means;
• D. discharging the liquid continuum containing solids from the comminuting means at an end substantially opposite the circulation to the comminuting means into a second retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour until a batch is provided in the second retaining chamber;
• E. thereafter recirculating the liquid continuum containing solids from the second retaining chamber into the comminuting means at one end thereof at a rate of at least about 30 volumes of the liquid continuum containing solids in the comminuting means per hour;
• F. grinding said solids in the comminuting means as in step C as the recirculated liquid continuum steadily passes through the comminuting means;
• G. discharging the liquid continuum containing solids from the comminuting means at an end substantially opposite the recirculation to the means into a third retaining chamber at a streaming speed of at least about 30 volumes of liquid continuum containing solids in the comminuting means per hour until a batch is provided in the third retaining chamber;
• and
• H. repeating steps B through G until the solids in the batch are reduced to desired particle size.