US3829280A - Apparatus for the production of polyphase gypsum - Google Patents

Apparatus for the production of polyphase gypsum Download PDF

Info

Publication number
US3829280A
US3829280A US00298009A US29800972A US3829280A US 3829280 A US3829280 A US 3829280A US 00298009 A US00298009 A US 00298009A US 29800972 A US29800972 A US 29800972A US 3829280 A US3829280 A US 3829280A
Authority
US
United States
Prior art keywords
cooling
cyclone
gypsum
discharge
dihydrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00298009A
Other languages
English (en)
Inventor
O Jenne
J Steinkuhl
O Wiechmann
G Reimann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rheinstahl AG
Original Assignee
Rheinstahl AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rheinstahl AG filed Critical Rheinstahl AG
Application granted granted Critical
Publication of US3829280A publication Critical patent/US3829280A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F11/00—Compounds of calcium, strontium, or barium
    • C01F11/46—Sulfates
    • C01F11/466—Conversion of one form of calcium sulfate to another
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B11/00—Calcium sulfate cements
    • C04B11/02—Methods and apparatus for dehydrating gypsum
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/54—Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer

Definitions

  • polyphase gypsum with an adjustable setting behavior is produced by first heating gypsum to form a phase mixture of dihydrate, hemihydrate and anhydrites.
  • the heating is carried out in a carrier gas burning plant with a burning gas temperature which is only slightly above the exit terminature of the burnt material and part of the anhydrite III, which is undesired in the end product, is then rehydrated to hemihydrate.
  • the rehydration of anhydrite III is effected by introducing the phase mixture into a cooling air current having an absolute humidity which can be regulated to about 30 g/Nm3 depending on the portion of the anhydrite III.
  • a known method of burning polyphase gypsum is carried out in a gas-burning plant, preferably with several series-connected cyclones, and the temperature of the entering heating gas current is regulated so that it is only slightly above the exit temperature of the burnt material, particularly 1.1 to 2 times higher, and the stay period of the material in the heating gas current is regulated to the range of from 0.5 to 10 seconds and the relative humidity of the heating gas current relative to the operating temperatures maintain to an amount of from 40 to 95 percent.
  • the raw material has a grain size of up to 2mm, with a preferred grain size of from to 400 1.1..
  • polyphase gypsums show relatively great variations intheir setting behavior even with careful supervision of the production process and this is obviously due to the metastable phases, particularly the metastable highly hygroscopic anhydrite Ill, undergoes substantially atransformation during storage by absorbing moisture from the air, in this case, to semihydrate. Since this process, called aging, depends to a great extend on the humidity, the temperature of the surrounding atmosphere and the time, this may lead to unforeseeable fluctuations in the setting behavior of the polyphase gypsum.
  • the shortcomings of the prior art in the manufacture of polyphase gypsums are overcome, and a method and apparatus is provided for the production of polyphase gypsums by which a very uniform and constant setting start and setting end may be obtained'and also particularly good physical properties of the resulting gypsum.
  • the invention provides a carrier gas burning method which permits the accurate production of polyphase gypsums of certain composition.
  • a phase mixture of dihydrate, hemihydrate and anhydrite is produced in a carrier gas burning plant with a burning gas temperature which is only slightly above the :exit temperature of the burnt material and that part of the anhydrite III which is undesired in the end product is rehydrated to hemihydrate.
  • the rehydration of anhydrite III is effected by introducing the phase mixture into a cooling air current having an absolute humidity which can be regulated in dependence upon the portion of the anhydrite III :up to about 30 g/Nm.
  • the rehydration of anhydrite III is effected by intensive admixture of fine grained dihydrate or dihydrate-containing substances to the phase mixture in such an amount that the water released .from the dihydrate corresponds to the 1.1 to 1.4 fold stoichometric amount which is necessary to 'rehydrate anhydrite III'to hemihydrate.
  • a particularly favorable embodiment of the invention comprises the rehydration of the :anh-ydrite III by adding to the phase mixture fine-grained dihydrate or dihydrate-containing substances and introducing the entire mixture into a wet or dry cooling .air current.
  • Another favorable embodiment -.of the invention comprises the rehydration of anhydrite lI'I byadding to apart of the phase mixture fine grained dihydrate -.or dihydrate-containing substances :while the other part is introduced simultaneously into a cooling air current with regulated humidity.
  • the metastable anhydrite III which is formed .in large quantities of up to 30 percent in the high-temperature burning of the gypsum, is converted by rehydration Lto vhemihydrate except for a small amount which is desired in the end product since it has a great stimulating effect on the beginning stiffening.
  • the other-wise unavoidable spontaneous conversion of anhydrite III is thus :no longer left to the accidental and slow action of "the humidity on the finished product. Rather, a finished stable end product is provided by the shock-like rehydration, whose setting behavior is not subject to fluctuations.
  • the apparatus for carrying out the method comprises I a mixing and conveying device arranged at the discharge of the burning cyclone and which opens into a discharge at its extreme end which leads to a cooling cyclone line.
  • a material discharge is connected into the conveyor downstream of the high temperature connection for dosing an amount of ground dihydrate or dihydrate-containing substances into the conveyor and mixing device.
  • the cooling line contains an adjustable air humidifier.
  • the material discharge of the cooling cyclone advantageously opens into a suction pipe leading to another cooling cyclone which can also be connected to a humidifier.
  • a further object of the invention is to provide a method for producing polyphase gypsums with an adjustable setting behavior wherein a phase mixture of dihydrate, hemihydrate and anhydrites is produced in a carrier gas burning plant with a burning gas temperature which is only slightly above the exit temperature of the burnt material and part of the anhydrite III which is undesired in the end product is then rehydrated to hemihydrate.
  • a further object of the invention is to provide a polyphase gypsum by effecting the rehydration of anhydrite III by adding to the phase mixture fine grained dihydrate or dihydrate-containing substances and introducing the entire mixture into a wet or dry cooling air current.
  • a further method of the invention is to produce a polyphase gypsum by effecting the rehydration of anhydrite III by introducing the phase mixture into a cooling air current whose absolute humidity can be regulated depending on the portion of anhydrite III to about 30 g/Nm
  • a further object of the invention is to provide an apparatus for producing polyphase gypsum which comprises at least one heating cyclone having a heating material discharge and which is heated by heating gases which are generated in a combustion device and transmitted to the cyclone and which includes a conveyor connected between the discharge of the cyclone to a cooling conduit and a separate storage bin for feeding additional material to the conveyor downstream of the high temperature heating cyclone and with a bypass for the high temperature heating cyclone for feeding the material directly into the cooling conduit.
  • a further object ,of the invention is to provide a method and apparatus for forming polyphase gypsum which is simple in design, rugged in construction and economical to manufacture.
  • FIGURE of the drawing is a schematic elevational view of a plant for manufacturing gypsum constructed in accordance with the invention.
  • the invention embodied therein comprises a finish burning cyclone 1 of a carrier gas burning plant into which heating gas is sucked by a fan (not shown) from a separate combustion device 2.
  • the finish burning cyclone 1 is charged from a preburning cyclone 4 having a discharge 4a regulated by a valve 41) which discharges into an inlet connection M for the finish burning cyclone 1.
  • Heating gases are connected through a conduit 22 back to the preburning cyclone 4 where they are employed for the preburning operation and then passed through a discharge 24.
  • Fine grained material (a dihydrate) is delivered to a bin 3, which has a discharge 3a, with a branch connection 3b connected to the return gas conduit 22 and a downpipe 7 which discharges downwardly.
  • a combined mixing and conveying device 6 for example in the form of a screw conveyor, is connected at its inlet end to a discharge connection 5 from the final burning cyclone 1 and it is provided with a discharge at its opposite end connected into a downwardly extending discharge 26 which leads into a cooling conduit or duct 10.
  • the downpipe 7from the bin 3 also connects into the combination mixing and conveying device 6 between the discharge 5 and the discharge 26.
  • Fine grained raw material (dihydrate and dihydrate-containing substances) can be added in adjustable amounts to the phase mixture produced in the carrier gas burning plants and discharged from the final burning cyclone 1 through the discharge 5.
  • Suitable valves 28 in the downpipes 7 and 30 in the bypass 3b are provided for controlling the amount of the additions and recycling of the material.
  • the cooling duct 10 is subjected to a suction produced by a fan 9 which connects to a cooling cyclone 8.
  • An adjustable humidifier 11 is also connected to the opposite end of the line 10.
  • the material is intentionally wetted in the line 10 and cooled by the intake air.
  • an adjustable bypass 21 interconnects the inlet end of the mixing and conveying device 6 with the cooling conduit 10 in order to provide for a feed directly from the discharge 5 of the final burning cyclone 1 into the cooling conduit.
  • the cooling cyclone 10 includes a discharge 12 which connects into a second cooling line 14 which is under the action of the suction fan 9 and which also connects to a second cooling cyclone 13.
  • This second cooling conduit 14 can be regulated by a regulating valve 15 so that it may be connected either to atmosphere or the humidifier 11 as desired.
  • the cooling air which is circulated into cyclones 8 and 13 are fed through lines 15 and 16 respectively after they provide their cooling function and are delivered into a dust separator 17 which, for example, can be a cloth filter.
  • the material which is in the cooling cyclone 13 is fed through a discharge 13a to a delivery conduit 19 along with material which is separated in the dust separator 17 which passes through the'discharge 18 into the conduit 19.
  • the delivery conduit 19 delivers the material into the finished goods bins, generally designated 20.
  • the apparatus can be operated so that the material issuing from the discharge 5 arrives in the cooling line without any admixture of dihydrate or dihydrate-containing substances merely by bypassing the combination mixing and conveying device 6 and delivering the material through the bypass 21 directly into the cooling conduit 10.
  • the material is then fed directly into the cooling conduit and through the cooling cyclones 8 and 13 and the anydraite III in rehydrated to hemihydrate by the humidity of the cooling air while the material is cooled at the same time.
  • the cooling conduit 13 can be operated with dry cooling air by disconnecting the humidifier.
  • the amount of dihydrate or dihydratecontaining substances necessary for the rehydration of anhydrite III is added through the line 7 to the material which is moved in the combination mixing and conveying device 6.
  • This mixture is then treated in the cooling conduit 10 and the cyclones 8 and 13 with humid air or dry air and, at the same time, it becomes cooled. It is possible to cool with dry air in the two cyclones 8 and 13 and, in such an instance, the humidifier 11 is shut down.
  • the humidifier l1 advantageously includes an inlet 11a for air, a water spray 11b and a water receiving trough 110.
  • a still further method of operation is possible by directing only a part of the material which arrives through the discharge 5 into the combined mixing and conveying device 6 through the bypass 21 directly into the cooling air line 10 and delivering a further part through the discharge 26 at the opposite end of the conveyor. In this manner, an amount of dihydrate or dihydrate-containing substances necessary for the rehydration of anhydrite III is added through the line 7 to the part of the mixture which is delivered through the discharge 26.
  • the treated material When the plant is operated, the treated material is delivered to the bin ready for use and this is unlike the finished product produced according to the conventional methods.
  • the material delivered is always uniform and will exhibit very little change in composition and setting power during the complete operation of the plant.
  • the material is cooled to a temperature which permits immediate packing into bags.
  • An apparatus for producing polyphase gypsum comprising at least one heating cyclone having a vertically extending heated material discharge pipe, means for supplying heating gases to said cyclone, a raw material storage bin for fine grained dihydrate material having a vertically extending dihydrate material discharge pipe extending substantially parallel to and spaced from said heated material discharge, a cooling conduit, a conveyor arranged below said heated material discharge pipe and solid dihydrate material discharge pipe and connected to said heated material discharge and to said fine grained material discharge at spaced locations in series and having a final discharge connected into said cooling conduit.
  • An apparatus for producing polyphase gypsum including a bypass connected to said heated material discharge and connecting directly into said cooling conduit.
  • An apparatus for producing polyphase gypsum including a first cooling cyclone connected to said cooling conduit and having a first cooling cyclone discharge, a second cooling cyclone connected to the discharge of said first cooling cyclone, a humidifier having-an inlet for air connected to said cooling conduit and having a connection to said second cooling cyclone, and adjustable means in the connection to said second cooling cyclone for connecting and disconnecting said second cooling cyclone to the humidifier and to atmosphere.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Compositions Of Oxide Ceramics (AREA)
US00298009A 1972-01-07 1972-10-16 Apparatus for the production of polyphase gypsum Expired - Lifetime US3829280A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19722200532 DE2200532A1 (de) 1972-01-07 1972-01-07 Verfahren und vorrichtung zum herstellen von mehrphasengipsen

Publications (1)

Publication Number Publication Date
US3829280A true US3829280A (en) 1974-08-13

Family

ID=5832427

Family Applications (1)

Application Number Title Priority Date Filing Date
US00298009A Expired - Lifetime US3829280A (en) 1972-01-07 1972-10-16 Apparatus for the production of polyphase gypsum

Country Status (8)

Country Link
US (1) US3829280A (xx)
JP (1) JPS5219559B2 (xx)
AT (1) AT328948B (xx)
BE (1) BE793693A (xx)
CH (1) CH585677A5 (xx)
DE (1) DE2200532A1 (xx)
FR (1) FR2166919A5 (xx)
GB (1) GB1400830A (xx)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4080422A (en) * 1975-06-30 1978-03-21 United States Gypsum Company Method for producing insoluble calcium sulfate anhydrite
US4569831A (en) * 1985-04-01 1986-02-11 Fuller Company Process and apparatus for calcining gypsum
US20110011311A1 (en) * 2006-12-20 2011-01-20 Robert Byron Bruce Calcium sulfate hemihydrate treatment process
US20110150750A1 (en) * 2008-05-09 2011-06-23 Claudius Peters Technologies Gmbh Calcination method and system
US8793897B2 (en) 2010-08-11 2014-08-05 Grenzebach Bsh Gmbh Process and device for stabilising, cooling and dehumidifying gypsum plaster
US10974993B2 (en) * 2016-02-02 2021-04-13 Yoshino Gypsum Co., Ltd. Calcined gypsum treatment device and calcined gypsum treatment method

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2276276A1 (fr) * 1974-06-28 1976-01-23 Rhone Poulenc Ind Procede de preparation de platre
GB2140702A (en) * 1980-11-10 1984-12-05 Bpb Industries Plc Fluidised bed calcination
WO2007065527A2 (fr) * 2005-12-07 2007-06-14 Gypsmix (Sarl) Procede pour stabiliser de l’anhydrite iii soluble metastable, procede de preparation d’un liant hydraulique a base d’anhydrite iii soluble stabilise, liant hydraulique obtenu, utilisation de ce liant et installation industrielle pour la mise en oeuvre d’un tel procede
DE102010033988A1 (de) * 2010-08-11 2012-02-16 Grenzebach Bsh Gmbh Verfahren und Vorrichtung zur Stabilisierung, Kühlung und Entfeuchtung von Stuckgips
EP2894135A1 (en) * 2014-01-10 2015-07-15 Saint-Gobain Placo SAS Method of curing a gypsum calcination product

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4080422A (en) * 1975-06-30 1978-03-21 United States Gypsum Company Method for producing insoluble calcium sulfate anhydrite
US4569831A (en) * 1985-04-01 1986-02-11 Fuller Company Process and apparatus for calcining gypsum
US20110011311A1 (en) * 2006-12-20 2011-01-20 Robert Byron Bruce Calcium sulfate hemihydrate treatment process
US8282731B2 (en) 2006-12-20 2012-10-09 The Nugyp Corp. Calcium sulfate hemihydrate treatment process
US20110150750A1 (en) * 2008-05-09 2011-06-23 Claudius Peters Technologies Gmbh Calcination method and system
US8793897B2 (en) 2010-08-11 2014-08-05 Grenzebach Bsh Gmbh Process and device for stabilising, cooling and dehumidifying gypsum plaster
US10974993B2 (en) * 2016-02-02 2021-04-13 Yoshino Gypsum Co., Ltd. Calcined gypsum treatment device and calcined gypsum treatment method

Also Published As

Publication number Publication date
DE2200532A1 (de) 1973-07-12
JPS4874497A (xx) 1973-10-06
CH585677A5 (xx) 1977-03-15
JPS5219559B2 (xx) 1977-05-28
GB1400830A (en) 1975-07-23
ATA884372A (de) 1975-06-15
BE793693A (fr) 1973-05-02
AT328948B (de) 1976-04-12
FR2166919A5 (xx) 1973-08-17

Similar Documents

Publication Publication Date Title
US3829280A (en) Apparatus for the production of polyphase gypsum
CN101252997B (zh) 用于碾磨热湿生料的方法和装置
US4569831A (en) Process and apparatus for calcining gypsum
US4026717A (en) Economical, finely controlled cement production
US3956456A (en) Gypsum calcination
US3648994A (en) Process for calcining gypsum in a current of heating gas
CA2737065C (en) Method and system for the production of hard plaster
GB2118924A (en) Method of and apparatus for reducing the sulphur circulation and/or the so2 emission in a plant for burning fine-grained material
NO145137B (no) (1-fenyl-2-triazolyl-etyl)-eter-derivater samt deres anvendelse som fungicider
US3773892A (en) Method and apparatus for burning gypsum
US4236932A (en) Method and apparatus for producing a hydraulic binder
EA007418B1 (ru) Способ и устройство для получения цемента
US4045162A (en) Method of burning granular or pulverulent raw material and kiln plant therefor
CZ281929B6 (cs) Způsob výroby tekuté anhydritové sádry na mazaniny a zařízení k její výrobě
US5449404A (en) Method for manufacturing cement
US4878949A (en) Method for the production of cement clinker from semi-wet raw material
US3986820A (en) Method and apparatus for burning multiphase gypsum
US4146360A (en) Device for controlling the gas temperature in the drying chamber of a moving grate preheater for cement clinker production
JP2689502B2 (ja) 石膏焼成装置の製御方法
US4668182A (en) Apparatus for calcining gypsum
US3998596A (en) Apparatus for treating by-product gypsum to be used as an inhibitor for setting of cement
JPH1081515A (ja) 実質的に相が純粋なベータ半水石膏の調製方法
RU2783929C1 (ru) Способ производства портландцементного клинкера
RU2783930C1 (ru) Способ производства портландцементного клинкера
US3183106A (en) Method of making cement