CA1112425A - Production of hydrochloric acid - Google Patents
Production of hydrochloric acidInfo
- Publication number
- CA1112425A CA1112425A CA312,849A CA312849A CA1112425A CA 1112425 A CA1112425 A CA 1112425A CA 312849 A CA312849 A CA 312849A CA 1112425 A CA1112425 A CA 1112425A
- Authority
- CA
- Canada
- Prior art keywords
- calcium chloride
- silica
- sio2
- hydrochloric acid
- production
- 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
Links
Classifications
-
- 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
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/02—Granular materials, e.g. microballoons
- C04B14/04—Silica-rich materials; Silicates
- C04B14/043—Alkaline-earth metal silicates, e.g. wollastonite
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/24—Alkaline-earth metal silicates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B7/00—Halogens; Halogen acids
- C01B7/01—Chlorine; Hydrogen chloride
- C01B7/03—Preparation from chlorides
- C01B7/035—Preparation of hydrogen chloride from chlorides
-
- 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
- C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B18/04—Waste materials; Refuse
- C04B18/0481—Other specific industrial waste materials not provided for elsewhere in C04B18/00
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Civil Engineering (AREA)
- Inorganic Chemistry (AREA)
- Environmental & Geological Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Silicon Compounds (AREA)
- Processing Of Solid Wastes (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
ABSTRACT
A method for the production of HC1 comprises heating calcium chloride with a molar excess of SiO2 having a surface area of at least 15m2/gm at a tem-perature in excess of 600°C in the presence of water vapour, suitably in a fluidized bed reactor. Silica residues from acid processes, and calcium chloride waste, may advantageously be used. By-product CaSiO3 is also useful for thermal insulation.
A method for the production of HC1 comprises heating calcium chloride with a molar excess of SiO2 having a surface area of at least 15m2/gm at a tem-perature in excess of 600°C in the presence of water vapour, suitably in a fluidized bed reactor. Silica residues from acid processes, and calcium chloride waste, may advantageously be used. By-product CaSiO3 is also useful for thermal insulation.
Description
~i$'~4Z5 "PRODUCrION OF HYDROCHLORIC ACID"
~ he present invention relate~ to the production of hydrochloric acid. ~arge quantities of hydrochloric acid are used in many chemical processes and a process capable cf producing hydrochloric acid from essentially waste materials without exces~i~ely large ener~y input is of obvious commercial interest.
In many processes, e.g. Solvay soda-ash process or in procefises employing h~drochloric acid as a proce~s feed material, large quantities of calcium chloride are produced as a waste material, which presents some dis-posal problems because of its high solubility.
method which enables hydrochloric acid to be produced from ~uch waste Ca~l2 and which at the ~ame time con-verts the calcium chloride into an innocuous and, insome circumstances, useful material has obvious attrac-tions.
It i~ already known that cP1cium chloride can be broke~ down into HCl gas by heating calcium chloride to temperaturas in excess of 1100C in the presence of ~ater vapour. ~he heat energy and the temperature re~uired for the process can be considexably reduced ~y carrying out the py~ohydxolysis of CaC12 in the pre~ence of silica. ~he reaction of CaO with ~iO2 is exothermic, so that the intxoduction of silica into the xeaction leads to a re~uction in the ener~y requireme~.
~k - When this apparently attractive process ~as put into commercial operation by heating a mixture of CaCl2 and ground quartz in the presence of water, at high tem-perature, the results were disappointi~g in commercial term~. The rate of reaction was unduly slow and the quartz, wher entrained in the off-ga~ stream, was very abrasi~e to the apparatus. In consequence it was considered that this procedure was not quite commer-cially ~iable for the production of h~vdrochloric acid.
In processes for the recovery of alumina ~alues from siliceous minerals by attack with strong aqueou~
acids, such as sulphuric acid and hydrochloric acid, large proportions of the thus decomposed silicates are converted into very finely divided and porous amorphous silica. We ha~re appreciated that, although in normal terms they may be considered inert, these silica wa~tes are far more reactive with alkaline materials at high temperature than the ground quartz employed in the unsuccessful process alread~ referred to and moreover these wastes are essentially non-crystalline and the particles are of very small mass, so that they exert far less abrasive effect if they become entrained in the air stream, employed to carry water ~apour in the pyrohydrolysis of calcium chloride. Also, the silica wastes have a large internal surface (porosity) while the ~uartz crystals are acti~e on their external surface only.
~ he ground ~uartz (-200 mesh) of the prior proces~ had a ~urface area of about 0~5m2 to 1.0m2/gm.
By contrast, the siliGa residues from acid procesqe~
for ~xample, resulting from acid treatment of anortho-Rite (ground to -200 mesh) or clay, has a surface area of ~t least 20m2/gm and more usually of 30 to 60m2/gm, dependin~ on the source of the siliceous mineral tre~ted and ths co~ditions employed i~ ~he acid attack.
Surface area/g~ and particle size are, of course, related parameter~.
Normally, the silica residues from acid pxoce~ses are difficult to wash and must be carefully neutralized for safe disposal. The pre~ent process eliminates the need for complete wash and neutrali-zation.
We have found that CaCl2 may be pyro~vdrolyzed to a very large extent, e.g. 9~h or more, more rapidly or at lower temperature than when pyrohydrolyzed in the presence of ground quartz. Ac~ording to the present invention a method for production of ~Cl comprises heating calcium chloride with a molar excess of SiO2 having a surface area of at least 15m /gm at a temper-ature in exces~ of 600G in the pre~ence of watervapour. ~he process temperature preferably does not much exceed 1000C, since this increases equipment &nd energy requirements. Depending on the temperature, the surface area Or the SiO2 and upon the excess of water ~0 vapour employed, it is usually possible to achieve 9~/o conversion of CaC12 to HCl i~ a process time in the range of 20-100 minutes in a static bed end raster in a fluidized bed operation.
In a convenient commercial ~peration a mixture Or calcium chloride and active siliceous waste Or the type discussed is briquetted and reacted with a stre~m of ~team in a rluidized bed reactor or is progressed through a tunnel~ a rota~y kiln or other type of furnace.
~he molar ratio of CaCl2:SiO2 in the mix is generally in the range of 0.25-0.90, 0~90 ~eing preferred for heat-econo~y reasons. A typical dwell time of the materi~l at the reaction temperature is 30 minute~ with the ~emperature being adJusted to obtain at least 9~ and more pre~erably 95,~ conver~ion o~ calciu~ chloride into ~l. A~ternati~ely the dwell time o~ the CaCl2/active , ~ .
~l~Z~25 SiO2 mixture at the reaction temperature m~y be adjusted in relation to a predetermined reaction tem-perature to achieve a predetermined percentage con-version or a predetermined HCl/H20 ratio in the product gas.
We have found that the product of the reaction between CaC12 ~nd SiO2 is alpha-C~SiO3, which is produced in a very porous form and has usefulness as a thermal insulation at temperatures up to its melting point (about 1500C). Its usefulne~s for these and other pu~poses is dependent on the amount of free SiO2 present which in turn depends upon the molar excess of SiO2 employed in the process.
In one series of tests the following results were obtained when CaCl2/active SiO2 waste in briquetted form was heated in a glow-bar furnace in an atmo~phere saturated with water vapour.
_ l h h ~ 0 ;i (~ U~
~æ ~ ~ cl~ ~ ~ ~ ~
_ . .
~ O
:3 _ _ .
.r ~ O O L~ ~ I
0 $ $ ~ ~ D
~ æ ~
a ~ ~ ~ D 0 ., ~r ~ O O ~ ~~ O
~dC` (~ ~D O IS~
r~l _ ,n . C~
H ~ O o o o O O
Q) O O O O O O
~ ~~ O ~ 0 0 1 r _ ~ ~ r . .. _ ~ ~ $ ~
h .
r l U~ O
~0 ~ <~ I 0 O , O O O O O O
C> .Q
' _ ~UO
~d C~ _ =
~ :~ ~ ~
~ ~_ __ . _ .. _._ .
n ~ ~ ~
. _ _ ~ _ _ + ~ _ ~12~25 Waste A is an active silica waste, resulting from the dige~tion of anorthosite with h~drochloric acid in the pre~ence of calcium ~nd fluoride ions, as described in our co-pending Patent Application No.
Waste B is an active silica waste, resulting from the digestion of kaolin with sulphuric acid to extract alumina ~alues therefrom.
By contrast with tne nearly complete conversion of CaC12 into hydrochloric acid under the conditions set out above it was found that when ~ mixture of NaCl and Waste A in a molar ratio of 0.25 was heated for 60 minutes at temperatures of 900-1100C in the prese~ce of a stre~m of wet air the conversion of ~aCl was only 1 5 22-3~o.
~ he process of the present invention provides a cheap and convenient route for the production of hydrochloric acid and for the disposal of calcium chloride waste. It i8 particularly convenient as a means for regenerating hydrochloric acid~ in processes such as that described in our co-pending Patent Appli-cation No. ~/2 ~ ~ , in which calcium chloride and active silica wa~t-es arise as the result of digestion of a siliceous mineral with hydrochloric acid.
In another series of experiments siliceous residues obtained by the acid treatment of anorthosite, as described in our co-pending Patent Application - No. ~ ~ were heated in the presence o~ water vapour with impure CaCl2, obtained by heating to dryness part of the spent process liquor ~after precipitation of AlCl3). ~he impure CaCl2 contained approximately ~o MgC12, ~o ~eC13 and 1% TiC13. The conversion efficiency wa~ compared with resu~ts obtai~ed by heating fine~y ground quartz ~-200 mesh) with CaC12.
The results of these tests are ~u~marized in
~ he present invention relate~ to the production of hydrochloric acid. ~arge quantities of hydrochloric acid are used in many chemical processes and a process capable cf producing hydrochloric acid from essentially waste materials without exces~i~ely large ener~y input is of obvious commercial interest.
In many processes, e.g. Solvay soda-ash process or in procefises employing h~drochloric acid as a proce~s feed material, large quantities of calcium chloride are produced as a waste material, which presents some dis-posal problems because of its high solubility.
method which enables hydrochloric acid to be produced from ~uch waste Ca~l2 and which at the ~ame time con-verts the calcium chloride into an innocuous and, insome circumstances, useful material has obvious attrac-tions.
It i~ already known that cP1cium chloride can be broke~ down into HCl gas by heating calcium chloride to temperaturas in excess of 1100C in the presence of ~ater vapour. ~he heat energy and the temperature re~uired for the process can be considexably reduced ~y carrying out the py~ohydxolysis of CaC12 in the pre~ence of silica. ~he reaction of CaO with ~iO2 is exothermic, so that the intxoduction of silica into the xeaction leads to a re~uction in the ener~y requireme~.
~k - When this apparently attractive process ~as put into commercial operation by heating a mixture of CaCl2 and ground quartz in the presence of water, at high tem-perature, the results were disappointi~g in commercial term~. The rate of reaction was unduly slow and the quartz, wher entrained in the off-ga~ stream, was very abrasi~e to the apparatus. In consequence it was considered that this procedure was not quite commer-cially ~iable for the production of h~vdrochloric acid.
In processes for the recovery of alumina ~alues from siliceous minerals by attack with strong aqueou~
acids, such as sulphuric acid and hydrochloric acid, large proportions of the thus decomposed silicates are converted into very finely divided and porous amorphous silica. We ha~re appreciated that, although in normal terms they may be considered inert, these silica wa~tes are far more reactive with alkaline materials at high temperature than the ground quartz employed in the unsuccessful process alread~ referred to and moreover these wastes are essentially non-crystalline and the particles are of very small mass, so that they exert far less abrasive effect if they become entrained in the air stream, employed to carry water ~apour in the pyrohydrolysis of calcium chloride. Also, the silica wastes have a large internal surface (porosity) while the ~uartz crystals are acti~e on their external surface only.
~ he ground ~uartz (-200 mesh) of the prior proces~ had a ~urface area of about 0~5m2 to 1.0m2/gm.
By contrast, the siliGa residues from acid procesqe~
for ~xample, resulting from acid treatment of anortho-Rite (ground to -200 mesh) or clay, has a surface area of ~t least 20m2/gm and more usually of 30 to 60m2/gm, dependin~ on the source of the siliceous mineral tre~ted and ths co~ditions employed i~ ~he acid attack.
Surface area/g~ and particle size are, of course, related parameter~.
Normally, the silica residues from acid pxoce~ses are difficult to wash and must be carefully neutralized for safe disposal. The pre~ent process eliminates the need for complete wash and neutrali-zation.
We have found that CaCl2 may be pyro~vdrolyzed to a very large extent, e.g. 9~h or more, more rapidly or at lower temperature than when pyrohydrolyzed in the presence of ground quartz. Ac~ording to the present invention a method for production of ~Cl comprises heating calcium chloride with a molar excess of SiO2 having a surface area of at least 15m /gm at a temper-ature in exces~ of 600G in the pre~ence of watervapour. ~he process temperature preferably does not much exceed 1000C, since this increases equipment &nd energy requirements. Depending on the temperature, the surface area Or the SiO2 and upon the excess of water ~0 vapour employed, it is usually possible to achieve 9~/o conversion of CaC12 to HCl i~ a process time in the range of 20-100 minutes in a static bed end raster in a fluidized bed operation.
In a convenient commercial ~peration a mixture Or calcium chloride and active siliceous waste Or the type discussed is briquetted and reacted with a stre~m of ~team in a rluidized bed reactor or is progressed through a tunnel~ a rota~y kiln or other type of furnace.
~he molar ratio of CaCl2:SiO2 in the mix is generally in the range of 0.25-0.90, 0~90 ~eing preferred for heat-econo~y reasons. A typical dwell time of the materi~l at the reaction temperature is 30 minute~ with the ~emperature being adJusted to obtain at least 9~ and more pre~erably 95,~ conver~ion o~ calciu~ chloride into ~l. A~ternati~ely the dwell time o~ the CaCl2/active , ~ .
~l~Z~25 SiO2 mixture at the reaction temperature m~y be adjusted in relation to a predetermined reaction tem-perature to achieve a predetermined percentage con-version or a predetermined HCl/H20 ratio in the product gas.
We have found that the product of the reaction between CaC12 ~nd SiO2 is alpha-C~SiO3, which is produced in a very porous form and has usefulness as a thermal insulation at temperatures up to its melting point (about 1500C). Its usefulne~s for these and other pu~poses is dependent on the amount of free SiO2 present which in turn depends upon the molar excess of SiO2 employed in the process.
In one series of tests the following results were obtained when CaCl2/active SiO2 waste in briquetted form was heated in a glow-bar furnace in an atmo~phere saturated with water vapour.
_ l h h ~ 0 ;i (~ U~
~æ ~ ~ cl~ ~ ~ ~ ~
_ . .
~ O
:3 _ _ .
.r ~ O O L~ ~ I
0 $ $ ~ ~ D
~ æ ~
a ~ ~ ~ D 0 ., ~r ~ O O ~ ~~ O
~dC` (~ ~D O IS~
r~l _ ,n . C~
H ~ O o o o O O
Q) O O O O O O
~ ~~ O ~ 0 0 1 r _ ~ ~ r . .. _ ~ ~ $ ~
h .
r l U~ O
~0 ~ <~ I 0 O , O O O O O O
C> .Q
' _ ~UO
~d C~ _ =
~ :~ ~ ~
~ ~_ __ . _ .. _._ .
n ~ ~ ~
. _ _ ~ _ _ + ~ _ ~12~25 Waste A is an active silica waste, resulting from the dige~tion of anorthosite with h~drochloric acid in the pre~ence of calcium ~nd fluoride ions, as described in our co-pending Patent Application No.
Waste B is an active silica waste, resulting from the digestion of kaolin with sulphuric acid to extract alumina ~alues therefrom.
By contrast with tne nearly complete conversion of CaC12 into hydrochloric acid under the conditions set out above it was found that when ~ mixture of NaCl and Waste A in a molar ratio of 0.25 was heated for 60 minutes at temperatures of 900-1100C in the prese~ce of a stre~m of wet air the conversion of ~aCl was only 1 5 22-3~o.
~ he process of the present invention provides a cheap and convenient route for the production of hydrochloric acid and for the disposal of calcium chloride waste. It i8 particularly convenient as a means for regenerating hydrochloric acid~ in processes such as that described in our co-pending Patent Appli-cation No. ~/2 ~ ~ , in which calcium chloride and active silica wa~t-es arise as the result of digestion of a siliceous mineral with hydrochloric acid.
In another series of experiments siliceous residues obtained by the acid treatment of anorthosite, as described in our co-pending Patent Application - No. ~ ~ were heated in the presence o~ water vapour with impure CaCl2, obtained by heating to dryness part of the spent process liquor ~after precipitation of AlCl3). ~he impure CaCl2 contained approximately ~o MgC12, ~o ~eC13 and 1% TiC13. The conversion efficiency wa~ compared with resu~ts obtai~ed by heating fine~y ground quartz ~-200 mesh) with CaC12.
The results of these tests are ~u~marized in
2;~
~able 2, from which it can be seen that the conversion efficiency achieved by reaction of quartz with CaCl2 can be obtained in the same treatment time by reaction of anorthosite residues with impure CaCl2 at a temper-ature approximately 100C lower.
Because of the known advantages of a fluidized bed, this type of operation was tried in the laboratory.
1~ inch diameter vertical tube was heated externally to 600C - 1000C. ~he bed wa~ loaded with 50 grams of calcium chloride - silica residue briquettes of 20 x 65 mesh size, the silica reæidue havin~ a surface area of greater than 15m2/~m. The fluidizing gas consisted of nitrogen containing 0.6 - 3.6% by weight of water and flowing at 25 litres per minute.
~he observed equilibrium constant agreed reason-ably well with the Ep calculated from the thermodynamic data. ~he reaction, at 800C, was completed in less than 30 minutes. ~he calculated thermal requirements, starting from solid, wet materials, ~re estimated at 550 - 750 x 106 cal./tonne of dry calcium chloride, which i~ quite favourable.
N
O ~ O ~D 0~ ~ t' ~ ~ ~ O~ O C' Lt~
N N ~ ~D 0 ~ ~ cr~ a~ ~u C~
p~
-- ~--~ --r Gq ~ 0 ~ O ~ Il~ N~ 0 0 ~ ~ 0 0 a~ 0 0~ 00 0 ~D u~ ~ ~ C' ~ ~ ~ ~ ~ D
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_ O ~ :~ ~ 0 t~ ~ N U'~ I
tS æ ~ ~ D ~ ~ O 0 0 ~ N 1~ U
~q _ P 0 ~ oo u~ ~ ~ ~ ~ ~ Lr~ D O u~ O u~
C' ~ O ~ ~ N 0 N 1~ ~ C~ C~
~able 2, from which it can be seen that the conversion efficiency achieved by reaction of quartz with CaCl2 can be obtained in the same treatment time by reaction of anorthosite residues with impure CaCl2 at a temper-ature approximately 100C lower.
Because of the known advantages of a fluidized bed, this type of operation was tried in the laboratory.
1~ inch diameter vertical tube was heated externally to 600C - 1000C. ~he bed wa~ loaded with 50 grams of calcium chloride - silica residue briquettes of 20 x 65 mesh size, the silica reæidue havin~ a surface area of greater than 15m2/~m. The fluidizing gas consisted of nitrogen containing 0.6 - 3.6% by weight of water and flowing at 25 litres per minute.
~he observed equilibrium constant agreed reason-ably well with the Ep calculated from the thermodynamic data. ~he reaction, at 800C, was completed in less than 30 minutes. ~he calculated thermal requirements, starting from solid, wet materials, ~re estimated at 550 - 750 x 106 cal./tonne of dry calcium chloride, which i~ quite favourable.
N
O ~ O ~D 0~ ~ t' ~ ~ ~ O~ O C' Lt~
N N ~ ~D 0 ~ ~ cr~ a~ ~u C~
p~
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Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS
1. A method for the production of HCl which method comprises heating calcium chloride with a molar excess of SiO2 having a surface area of at least 15m2/gm at a temperature in excess of 600°C in the presence of water vapour.
2. A method as claimed in claim 1, wherein the temperature is not more than 1000°C.
3. A method as claimed in claim 1, wherein the molar ratio of CaCl2:SiO2 is from 0.25 to 0.90.
4. A method as claimed in any one of claims 1 to 3, wherein a mixture of the calcium chloride and the silica is briquetted and reacted with a stream of steam in a fluidized bed reactor.
5. A method as claimed in any one of claims 1 to 3, wherein the silica has been obtained as a by-product from the recovery of alumina values by the acid treatment of a silica-alumina raw material.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB4191577 | 1977-10-07 | ||
| GB41915/77 | 1977-10-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1112425A true CA1112425A (en) | 1981-11-17 |
Family
ID=10421951
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA312,849A Expired CA1112425A (en) | 1977-10-07 | 1978-10-06 | Production of hydrochloric acid |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1112425A (en) |
| DE (1) | DE2842635C3 (en) |
| FR (1) | FR2405216A1 (en) |
| NO (1) | NO151540C (en) |
| SE (1) | SE427550B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6994836B2 (en) | 2002-08-23 | 2006-02-07 | President Of Shizuoka University | Method of recovering chlorine gas from calcium chloride |
-
1978
- 1978-09-29 DE DE2842635A patent/DE2842635C3/en not_active Expired
- 1978-10-06 CA CA312,849A patent/CA1112425A/en not_active Expired
- 1978-10-06 NO NO783396A patent/NO151540C/en unknown
- 1978-10-06 FR FR7828615A patent/FR2405216A1/en active Granted
- 1978-10-09 SE SE7810526A patent/SE427550B/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6994836B2 (en) | 2002-08-23 | 2006-02-07 | President Of Shizuoka University | Method of recovering chlorine gas from calcium chloride |
Also Published As
| Publication number | Publication date |
|---|---|
| NO151540B (en) | 1985-01-14 |
| DE2842635A1 (en) | 1979-04-12 |
| SE427550B (en) | 1983-04-18 |
| FR2405216B1 (en) | 1984-06-29 |
| FR2405216A1 (en) | 1979-05-04 |
| DE2842635B2 (en) | 1980-05-14 |
| DE2842635C3 (en) | 1981-02-05 |
| NO151540C (en) | 1985-05-02 |
| SE7810526L (en) | 1979-04-08 |
| NO783396L (en) | 1979-04-10 |
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