Fuller Company

Other

Gas Research Institute

Sidney M Cohen

Michael E Prokesch

William E Lindquist

Anthony F Litka

Barry Wayne Diamond

Gerald J Labelle

The invention relates to a method for heat treatment of fine calcium carbonate bearing material comprising preheating fine material containing a coarse and a fine fraction. The preheated material is delivered into a fluidized bed calcining means wherein the coarse fraction is calcined and the fine fraction is delivered by process air to an adjacent vertically arranged gas flash calciner furnace in which it is calcined.

Method for the calcination of calcium carbonate bearing materials

A process of treating dust from a cement manufacturing operation. The process comprises adding carbon bearing material to the dust catch from a cement manufacturing operation to form a mixture, which is formed into nodules and sizing the nodules to obtain a feed material having a selected size range. The nodules are directed as feed material to a fluidized bed which is maintained by passing air for combustion upwardly through a bed of material. The material is thermal processed within the fluidized bed in a reducing atmosphere by supplying fuel for combustion in the fluidized bed to maintain temperatures sufficient to volatilize alkali and sulfur compounds in the feed material and produce a product having an increased concentration of cement forming compounds and reduced alkali and sulfur compounds as compared to the feed material. The reduced clinker is then re-oxidized to minimize/reverse adverse color and mineralogy.

Cement dust recovery system

Disclosed is a method and an apparatus used in said method, to produce aggregate products from waste material streams. The method comprises combining an encapsulation material with waste materials to form a mix suitable for granulation. This mix is then feed to a granulation means to form particles having a size suitable for thermal treatment in a bed thermal processing means, which can be a fluid bed system or a spouting bed system. In the bed thermal processing apparatus the particles are converted into an aggregate product.

Method to produce aggregate products

Disclosed is a method and an apparatus for the heat treatment of lime sludge (CaCO.sub.3) to form burnt lime (CaO). In the method of the present invention lime sludge is dried in a gas dryer means, to produce a dried lime sludge. The dried lime sludge is separated from the gases and thereafter is first fed to a compacting means wherein it is compacted into a plurality of substantially uniform bodies which are thereafter fed to a shaft kiln in which the compacted dried lime sludge is converted to active burnt lime.

Apparatus for heat treatment of lime sludge

With the present invention, a feed preparation system for producing cement includes mixing raw materials with a source of potassium. The mixture is conveyed to feed preparation system where it is placed in condition for treatment in a fluidized bed reactor for thermal processing to produce cement clinker. The potassium combines with the SO.sub.2 generated in the process to form potassium sulfate solids that are filtered from the process gas stream before emission to the atmosphere to thereby reduce sulfur emissions from the fluid bed cement process. The starting material may include white cement raw meal, grey cement raw meal and cement kiln dusts.

Method for the reduction of SO.sub.2 emissions as generated by the fluid

Lime sludge treatment process

A process for the continuous production of a calcined product containing a high level of reactive oxide valves, from a preheated raw material containing calcium carbonate values, said process comprising,

Method for the calcination of limestone

A suspension shaft furnace and process for producing clinkers from discrete pellets of cement-forming batch materials, the furnace having a top vertical shaft section comprising a pellet-feeding and preheating zone, an intermediate fluidized bed section containing fuel inlet conduits for clinkering of the pellets in a fluidized bed, an air-permeable clinker-impermeable support for supporting the pellets as a fluidized bed, and a lower clinker-cooling section beneath the fluidized bed section. Clinker-discharge means permit the gravity flow of clinkers from the top of the fluidized bed down into a cooling zone in the cooling section. Air inlet means supply a combustion-supporting cooling gas up through the cooling zone, to cool the clinkers therein, and upstream through the fluidized bed section to support the combustion of fuel at the fuel inlet conduits. Heated combustion supporting gas passes upstream to the vertical shaft section to heat pellets being fed downstream and regulates their speed and dwell time prior to their entry into the fluidized bed section.

Cement advanced furnace and process

A method to operate a flash calcination unit with both atmosphere and temperature control is described for mineral processing requirements and other atmosphere controlled processes. The method can be used to process phosphate, gold ore or activated carbon. The critical steps of the method involve an initial mixing of fine material combined with stoichiometric burning using at least one staged combustion furnace in a vertically oriented suspension calcination furnace. This effects control of oxygen or atmosphere in the combustion furnace with attendant control of temperature in that furnace.

Method for heat treatment of fines with atmosphere control

A method and apparatus for producing cement which includes intermixing the cement forming raw materials with water, coal or coke cement as a binder and forming this mixture of materials into nodules by pelletizing or extrusion. The system is particularly designed for use in making white cement where raw materials low in coloring compound are used as raw feed. The nodules are then sized to obtain a feed material having a size range on the order of one quarter inch by 14 mesh which is suitable for use in a fluidized bed reactor. The nodulized raw material is thermally processed in a fluidized bed reactor at temperatures in the range of approximately 2500.degree. to 2700.degree. F. for white cement and 2350.degree.-2450.degree. F. for typical gray Portland Cement. The coal or coke mixed with the raw material serves to supply between 60% and 90% percent of the fuel required for the process with the remainder being supplied directly to the fluidized bed. This fuel serves to provide internal reduction conditions within the particles of material. The product is discharged from a fluidized bed and cooled in an indirect heat exchanger.

Method and apparatus for producing cement clinker including white cement

An apparatus and process for calcining gypsum is disclosed which utilizes a flash furnace for rapidly calcining fine particulate gypsum while the material is suspended in a stream of hot gas. The method and apparatus utilize a two-stage suspension preheater for utilizing waste gases from the calcining furnace for preheating raw material to be calcined and a two-stage suspension cooler for cooling hot calcined gypsum which is discharged from the calcining furnace. Spent cooling gas is supplied to the preheater for use in preheating the fresh gypsum to be calcined. The invention also contemplates recirculating a portion of the gypsum discharged from the furnace back to the furnace for further calcination. Hot product may be discharged directly from the furnace.

Apparatus for calcining gypsum

An improved process and apparatus for producing sintered material such as dead burned clay, dolomite, magnesite or periclase with the highest particle specific gravity capable from each material. A grinding mill produces raw material which is 100% minus 20 mesh. The ground raw material is supplied to a suspension type preheater and then to a stationary flash calcining system where the material is soft burned at temperatures in the range of 1000.degree. to 1200.degree. C. From the calcining system, the calcined material is immediately supplied to hot briquetting machine where briquettes or nodules are formed. The hot nodules at a temperature of approximately 800.degree. C. are then immediately supplied to a rotary kiln which serves as a sintering furnace where the soft burned material is dead burnt at a temperature in the range of 1650.degree. to 1850.degree. C. Hot spent combustion gas from the sintering furnace is supplied to the calcining furnace to serve as preheated secondary air for combustion. The spent hot gas from the calcining furnace is used in the suspension preheater to preheat the raw material.

Method and apparatus for producing dead burnt materials

The invention utilizes fluid bed air heaters for burning coarse solid fuels which supply heated gases to annular shaft kilns or double inclined shaft kilns. The solid fuels are introduced into a fluidized bed of inert material, such as sand, alumina or ash, through means of an air lock and the hot gases of combustion pass through a cyclone separator to remove solid materials, which can be reintroduced into the fluidized bed. The hot gases are injected into the kilns to supply heat as needed for calcining or burning limestone or similar materials. Temperature control of the gas leaving the fluid bed air heater and reduced contamination of the burned materials are disclosed advantages of the present invention.

Shaft kilns having fluid-bed air heater

A method and apparatus for producing cement which includes intermixing the cement forming raw materials with water, coal or coke and cement as a binder and forming this mixture of materials into nodules by pelletizing or extrusion. The system is particularly designed for use in making white cement where raw materials low in coloring compound are used as raw feed. The nodules are then sized to obtain a feed material having a size range on the order of one quarter inch by 14 mesh which is suitable for use in a fluidized bed reactor. The nodulized raw material is thermally processed in a fluidized bed reactor at temperatures in the range of approximately 2500.degree. to 2700.degree. F. for white cement and 2350.degree.-2450.degree. F. for typical gray Portland Cement. The coal or coke mixed with the raw material serves to supply between 60% and 90% precent of the fuel required for the process with the remainder being supplied directly to the fludized bed. This fuel serves to provide internal reduction conditions within the particles of material. The product is discharged from a fluidized bed and cooled in an indirect heat exchanger.

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Allentown, PA, United States of America

Sidney M Cohen