CA2091780A1 - Process for producing bentonite clays exhibiting enhanced solution viscosity properties - Google Patents
Process for producing bentonite clays exhibiting enhanced solution viscosity propertiesInfo
- Publication number
- CA2091780A1 CA2091780A1 CA002091780A CA2091780A CA2091780A1 CA 2091780 A1 CA2091780 A1 CA 2091780A1 CA 002091780 A CA002091780 A CA 002091780A CA 2091780 A CA2091780 A CA 2091780A CA 2091780 A1 CA2091780 A1 CA 2091780A1
- Authority
- CA
- Canada
- Prior art keywords
- bentonite
- crude
- sodium
- ore
- hydroxide
- 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.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 36
- 229910000278 bentonite Inorganic materials 0.000 title claims abstract description 34
- 239000000440 bentonite Substances 0.000 title claims abstract description 34
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 title claims abstract description 33
- 230000008569 process Effects 0.000 title claims abstract description 23
- 230000001747 exhibiting effect Effects 0.000 title 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims abstract description 37
- 229910000029 sodium carbonate Inorganic materials 0.000 claims abstract description 18
- 235000017550 sodium carbonate Nutrition 0.000 claims abstract description 18
- 238000001035 drying Methods 0.000 claims abstract description 10
- 238000010008 shearing Methods 0.000 claims abstract description 10
- 239000000203 mixture Substances 0.000 claims abstract description 6
- 238000010298 pulverizing process Methods 0.000 claims abstract description 5
- 150000003839 salts Chemical class 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 13
- 239000004927 clay Substances 0.000 claims description 12
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical group [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 9
- FQENQNTWSFEDLI-UHFFFAOYSA-J sodium diphosphate Chemical group [Na+].[Na+].[Na+].[Na+].[O-]P([O-])(=O)OP([O-])([O-])=O FQENQNTWSFEDLI-UHFFFAOYSA-J 0.000 claims description 9
- 235000019818 tetrasodium diphosphate Nutrition 0.000 claims description 9
- 229910000281 calcium bentonite Inorganic materials 0.000 claims description 8
- 239000007787 solid Substances 0.000 claims description 6
- 239000012190 activator Substances 0.000 claims description 5
- 239000002270 dispersing agent Substances 0.000 claims description 5
- 150000001768 cations Chemical class 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims description 3
- 239000002002 slurry Substances 0.000 claims description 3
- 150000003467 sulfuric acid derivatives Chemical class 0.000 claims description 3
- 150000004649 carbonic acid derivatives Chemical class 0.000 claims description 2
- 230000000737 periodic effect Effects 0.000 claims description 2
- 239000000126 substance Substances 0.000 claims description 2
- 229940001593 sodium carbonate Drugs 0.000 claims 4
- 150000008044 alkali metal hydroxides Chemical group 0.000 claims 1
- 230000002708 enhancing effect Effects 0.000 claims 1
- 239000000843 powder Substances 0.000 claims 1
- 239000000463 material Substances 0.000 abstract description 5
- 239000007864 aqueous solution Substances 0.000 abstract 1
- 235000012216 bentonite Nutrition 0.000 description 33
- 229940092782 bentonite Drugs 0.000 description 25
- 239000003513 alkali Substances 0.000 description 7
- 230000004913 activation Effects 0.000 description 6
- 238000003801 milling Methods 0.000 description 6
- 239000011734 sodium Substances 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- ONCZQWJXONKSMM-UHFFFAOYSA-N dialuminum;disodium;oxygen(2-);silicon(4+);hydrate Chemical compound O.[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[Na+].[Na+].[Al+3].[Al+3].[Si+4].[Si+4].[Si+4].[Si+4] ONCZQWJXONKSMM-UHFFFAOYSA-N 0.000 description 3
- 150000004679 hydroxides Chemical class 0.000 description 3
- 238000005342 ion exchange Methods 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 229910000280 sodium bentonite Inorganic materials 0.000 description 3
- 229940080314 sodium bentonite Drugs 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical group [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 229910001415 sodium ion Inorganic materials 0.000 description 2
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical group C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- -1 Na2C0 Chemical class 0.000 description 1
- 101100156763 Schizosaccharomyces pombe (strain 972 / ATCC 24843) wos2 gene Proteins 0.000 description 1
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 1
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000004567 concrete Substances 0.000 description 1
- 239000002537 cosmetic Substances 0.000 description 1
- GUJOJGAPFQRJSV-UHFFFAOYSA-N dialuminum;dioxosilane;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3].O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O GUJOJGAPFQRJSV-UHFFFAOYSA-N 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 239000003623 enhancer Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 239000011369 resultant mixture Substances 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 230000009974 thixotropic effect Effects 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- A61Q19/00—Preparations for care of the skin
-
- 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
- C01B33/26—Aluminium-containing silicates, i.e. silico-aluminates
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K8/00—Cosmetics or similar toiletry preparations
- A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
- A61K8/19—Cosmetics or similar toiletry preparations characterised by the composition containing inorganic ingredients
- A61K8/26—Aluminium; Compounds thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28C1/00—Apparatus or methods for obtaining or processing clay
-
- 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
- C04B14/10—Clay
- C04B14/104—Bentonite, e.g. montmorillonite
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/04—Aqueous well-drilling compositions
- C09K8/14—Clay-containing compositions
- C09K8/145—Clay-containing compositions characterised by the composition of the clay
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Organic Chemistry (AREA)
- Dispersion Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Ceramic Engineering (AREA)
- Civil Engineering (AREA)
- Birds (AREA)
- Epidemiology (AREA)
- Structural Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Dermatology (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Cosmetics (AREA)
- Metal Rolling (AREA)
Abstract
A process for upgrading a crude bentonite ore such that it can be used advantageously to prepare unusually high aqueous solution viscosities. This sequence comprises initially subjecting the crude ore to a working or shearing stage, followed by a drying step to about a 5 % moisture level. Na2CO3 is then dry-blended with the material, and the sequence is completed by subjecting the mix to a pulverizing step.
Description
W092/05t23 PCT/US91/~KX
2~91780 PROCESS FOR PRODUCING BENTONITE CLAYS
E~IE~ E~ANCED SOLUTION VISCOSITY PROPERTIES
Backaround of the Invention This invention relates to a process for preparing bentonite claysl which when dispersed in water produce unexpectedly high solution viscosities. Such characteristics are highly desirable in numerous '~ 10 commercial applications.
Bentonites are naturally occurring ores which are mined in various regions of the world. Since these materials ,' are highly colloidal and readily swell in water to form thixotropic,gels, they are well-known for use as visc06ity builders1 This result obtains because bentonites are platey-type clays having a micaceous sheet ,' structure. Such clays therefore are self-suspending, swelling and gelatinizing when mixed-with water. Because of these viscosity building characteristics, bentonites find ~ajor utility as viscosity enhancers or builders in such areas as drilling muds and fluids, concrete and mortar additives, foundry and molding sands, compacting ' agents for gravel and'sand as well as cosmetics.
Most natural bentonites are found in nature to exist in the~sodi'um and/or the calcium form. The performance of a ;calcium bentonite as a viscosity builder can often be enhanced by lts conversion to the sodium form.
Th-~prior~art details attempts to enhance the viscosity building characteristics of bentonite clays by several approaches.~ For the most part these involve working (or shearing) of the crude bentonite ore. The sequence generally calls for a (1) working, e.g. milling: (2) drying; and/or (3) pulverization sequence.
: ~.: . - ;. -:
,. , ., , ;, . ~ . ... .
wos2/os123 rl 8 ~ PCT/US91/~68 !
In some instances the use of an alkali pre-treatment is described to "activate" the clays, prior to the milling or working step.
Hentz, U.S. Patent No. 4,371,626 thus discloses that alkali "activation" is only required for high calcium bentonite clays. It is suggested that there is an ion exchange mechanism involved where the sodium ion from either NaOH or Na,CO, replaces the calcium ion. Hentz teaches that crude sodium bentonite can be upgraded with respect to its viscosity building characteristics, without alkali treatment, simply by (i) shearing the crude clay; (ii) drying the clay; and (iii) grinding/pulverizing the dried clay.
AIther, U.S. Patent No. 4,242,140 describes a process for upgrading crude clays of the bentonite type by (i) adding 1-10% by weight of NaOH or Na2CO, to the crude clay, or adding it during compacting step: (ii) compacting the activator treated material: and (iii) grinding.
No drying is required by the Alther process, the compacted clay requires no further drying, and is ground and screened to the desired mesh size.
Alther subsequently reviewed the state-of-the-art with respect to bentonite activation in a review article. He summarizes it as follows in "Improvement in Drill Mud Properti~es of Low Grade Bentonite by Simultaneous Chemical Activation and Compacting", INTERCERAM, Vol. MR
5, 1982, p. 503:
"state of the Art Activation methods that are presently used are the following: 1. Sodium carbonate is spread in dry or dissolved form (dissolved in water) over the previously ripped bentonite bed and worked into the clay with a disc or roto-tiller. The bed is then frequently reworked ,, ' .: :''~ '-
E~IE~ E~ANCED SOLUTION VISCOSITY PROPERTIES
Backaround of the Invention This invention relates to a process for preparing bentonite claysl which when dispersed in water produce unexpectedly high solution viscosities. Such characteristics are highly desirable in numerous '~ 10 commercial applications.
Bentonites are naturally occurring ores which are mined in various regions of the world. Since these materials ,' are highly colloidal and readily swell in water to form thixotropic,gels, they are well-known for use as visc06ity builders1 This result obtains because bentonites are platey-type clays having a micaceous sheet ,' structure. Such clays therefore are self-suspending, swelling and gelatinizing when mixed-with water. Because of these viscosity building characteristics, bentonites find ~ajor utility as viscosity enhancers or builders in such areas as drilling muds and fluids, concrete and mortar additives, foundry and molding sands, compacting ' agents for gravel and'sand as well as cosmetics.
Most natural bentonites are found in nature to exist in the~sodi'um and/or the calcium form. The performance of a ;calcium bentonite as a viscosity builder can often be enhanced by lts conversion to the sodium form.
Th-~prior~art details attempts to enhance the viscosity building characteristics of bentonite clays by several approaches.~ For the most part these involve working (or shearing) of the crude bentonite ore. The sequence generally calls for a (1) working, e.g. milling: (2) drying; and/or (3) pulverization sequence.
: ~.: . - ;. -:
,. , ., , ;, . ~ . ... .
wos2/os123 rl 8 ~ PCT/US91/~68 !
In some instances the use of an alkali pre-treatment is described to "activate" the clays, prior to the milling or working step.
Hentz, U.S. Patent No. 4,371,626 thus discloses that alkali "activation" is only required for high calcium bentonite clays. It is suggested that there is an ion exchange mechanism involved where the sodium ion from either NaOH or Na,CO, replaces the calcium ion. Hentz teaches that crude sodium bentonite can be upgraded with respect to its viscosity building characteristics, without alkali treatment, simply by (i) shearing the crude clay; (ii) drying the clay; and (iii) grinding/pulverizing the dried clay.
AIther, U.S. Patent No. 4,242,140 describes a process for upgrading crude clays of the bentonite type by (i) adding 1-10% by weight of NaOH or Na2CO, to the crude clay, or adding it during compacting step: (ii) compacting the activator treated material: and (iii) grinding.
No drying is required by the Alther process, the compacted clay requires no further drying, and is ground and screened to the desired mesh size.
Alther subsequently reviewed the state-of-the-art with respect to bentonite activation in a review article. He summarizes it as follows in "Improvement in Drill Mud Properti~es of Low Grade Bentonite by Simultaneous Chemical Activation and Compacting", INTERCERAM, Vol. MR
5, 1982, p. 503:
"state of the Art Activation methods that are presently used are the following: 1. Sodium carbonate is spread in dry or dissolved form (dissolved in water) over the previously ripped bentonite bed and worked into the clay with a disc or roto-tiller. The bed is then frequently reworked ,, ' .: :''~ '-
3 ~0 9 1 7 8 o PCT/US9l/06468 i over a period of several months to improve homogeneity. The sodium carbonate, if spread over the bed in dry form, will dissolve, due to the bentonite's inherent moisture, rain, water and snow. When activation is performed on the stockpile, a layer of 15 cm to 20 cm of bentonite is deposited. Sodium carbonate is then spread or sprinkled onto this layer, followed by discing. These steps are then repeated until the desired stockpile size is achie l. 2. Where bentonites are not field-dried, sodium carbonate may be added to wet crude bentonite en route to an extruder or multiple extruder stages, followed by drying.
It is common to add water in addition to sodium carbonate to facilitate extrusion. The shearing action disorients the particles and increases the ion exchange. Here the bentonite is not dried and moisture is reduced to approximately 20% after extrusion. 3. The bentonite is first passed through a mechanical kneader, which works the sodium carbonate into the bentonite, and then steam is passed through the clay. The steam, whose low viscosity allows it to penetrate the clay aggregates, will split them and thus allow penetration and ion exchange. In addition the mobility of sodium ions is increased due to the action of the steam, increasing the exchange rate. 4. A
pug mill may also be used, whereby the soda ash is sprinkled onto a field-dried benton~te during its stay on the conveyor belt, with subsequent pugging. Most of the above-listed methods have these parameters in common: they either require time, a large amount of energy, and lots of water, or all three parameters together. The author found that when a bentonite is compacted, while sodium carbonate is simultaneously being added, not only are time and energy saved, but the API properties (viscosity and water loss) appear to improve much more than with the use of traditional ~methods."
45 Lang, U.S. Patent No. 3,700,474 teaches that the crude bentonite clays can be made more readily water disper-sible by compacting the clay which has been previously pulverized. However, no mention is made in either the specification or claims with respect to the need for any drying sequence or addition of alkali or salt.
:
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WO92/05123 PCT/US91/~68 2~9~ 80 4 Goodman et al, U.S. 4,483,934 describes a method of beneficiating raw bentonite ore to improve its color.
This involves the alkali treatment of the ore, working, shearing by milling followed by drying of the product.
It should be noted that in all the cases cited above, the prior art employs the use of an alkali or salt treatment as an "activator", either prior to or during the early milling or "working" stage of the sequence. In no in-stance is the addition of alkali considered or describedas being added at the last step of the sequence, such as at "dry-blend", prior to pulverization, and as a matter of fact, such would be highly contrary to the prior art teachings.
Summary of the Invention It has now been unexpectedly found that by shifting the processing sequence from that described in the prior art, we can obtain a significantly enhanced sodium bentonite capable of unusually high solution viscosities.
The sequence that we have discovered unexpectedly represents a total reversal of the state-of-the art pro-cedures and theories. This results in an unanticipatedincrease in the solution viscosity of a solution prepared ; ~ ~ with this inverted bentonite treatment.
The present invention calls for the initial working by shearing of a 20 to 50% water slurry of the crude ore, which has not had any salt treatment. The resultant product is then subsequently dried to about a 5 to 15~
moisture level, preferably to about 5 to 10%, and more preferably to about 5 to 6% moisture. To this dried bentonite material is then added a "bentonite-activating"
metal salt or hydroxide, typical of which is Na,CO,. The dry-blend is then pulverized. The preferred Na,C0, salt '' ., . ~ , WO92/~5123 PCT/US91/~U*
~ 0 91 78 0 is added in the general range of from 3 to 5%, although with certain crudes up to as much as 8% to 10% Na2C0, can be useful.
Although both calcium bentonite and mixtures of calcium bentonite and sodium bentonite can benefit from the invention, it is preferred to use a predominantly calcium bentonite as the starting crude.
In accordance with the foregoing, it may be regarded as an object of the present invention, to provide a process modification which significantly improves (increases) the viscosity characteristics of aqueous bentonite solutions.
It is a further object of the invention to provide a method of upgrading bentonites, particularly calcium bentonites, without the need for any preliminary, lengthy aging/ activation treatment.
Description of the Preferred Embodiment According to a preferred embodiment of this invention, the crude bentonite is initially subjected to shearing in a pug mill. Three or more passes through the milling process are often beneficial, but may not be required for many bentonites, wherein but a single pass confers most of the benefits of the invention. The pug mill can, for example, be of the type desc;ibed in U.S. Patent No.
3,574,345.
The sheared product thus obtained is then dried to a moisture level of about 5 to 6%; although higher levels of moisture can be used, up to 10 to 15%.
The dried product obtained at this stage of the sequence is then dry-blended or mixed with preferably about 3-5%
Na,C0, (in some instances up to about 8-10~ Na2C0, by .
~ , ' ~,' ' '' ~ ' .
W092/05123 PCT/US91/~U~
weight can be beneficial), and the resultant mixture is then pulverized. This is distinguished from the prior art since the Na2C0, salt in this case is added, by simple dry-blending, at the end of the process. The prior art teaches addition of salts such as Na2C0,, either to the ore stage or during the initial milling stage to activate the ore.
According to a further aspect of this invention, the following broad category of bentonite-activator salts and hydroxides will be effective in meeting the objectives of the invention:
Group IA periodic table cations including Na, Li~, ~ and Cs~ in soluble salts and hydroxides, including carbonates and sulfates are considered useful. In Group IIA cations, Mg~ in soluble salt form is useful. The transitional metals, Ni~, Zn~, Cu~ and possibly Co~ are considered useful. The above cations will be available as carbonate and sulfate salts or hydroxides. In specific instances, (NH,),C0" Al,(S0,), and Fe,(S0,), may be useful activators fF certain clays.
The preferred treatment of this invention involves the use of Na,C0" which has been found to give the most bene-ficial results.~ The level of salt addition which has been found to be most effective is broadly between 1~ and 10% based on the weight of bentonite; a preferred range is from 3 to 5% by weight, with the optimum level being about 5%.
Additionally, the embodiment of this invention may also ~include, but is not limited to, the use of an optional dispersing agent during the shearing step, such as tetrasodium pyrophosphate (TSPP) in amounts between about 1-5% by weight of the dry bentonite.
.
.. . .
WO92/05123 PCT/US91/~68 7 209178~
The invention is further illustrated by the following Examples, which are deemed to be illustrative, and not delimitive of the invention otherwise set forth.
A sample of a crude predominantly calcium bentonite clay wet cake containing 35% moisture and 2% tetrasodium pyro-phosphate dispersant was sheared by being subject to one pass through a conventional pug mill, of the type aforementioned. The energy dissipated in the pass through the pug mill was about 30 Hp-hr/ton of dry solids. Upon completion of this working step, the material was dried in a Blue M oven until the moisture content was reduced to about 5%. The sample was then dry blended with 3% Na,CO, and then pulverized. The sample was then added to water such that the solution répresented 5% solids level. Brookfield viscosity data was measured at 30-C using a No. 3 spindle, as llO0 cps.
~!~iL
The processing conditions of Example l were repeated, except that during the pugging step no TSPP was used.
Instead, 2% TSPP, together with 3% sodium carbonate, were ; dry blended with the sample from the oven. The resulting Brookfield viscosity (No. 2 spindle) was 555 cps. (In all of Examples l to 7, the same crude was used.) ExAMpLE 3 ;
The conditions of Example 2 were repeated, except that no TSPP was used and 5% sodium carbonaté was dry blended with the oven dried sample. The ~easured Brookfield viscosity (No. 3 spindle) was 1438 cps.
:
~ , : . , , .: :
"
W092tO5123 PCT/US91/~68 209178~ 8 The procedure in this Example constituted a conventional processing and was a control. Specifically in this instance, a sample of the same crude bentonite clay, as in Example 1, was subjected to one pass through the pug mill in the presence therein of 5% sodium carbonate. The resulting product was dried as in Example 1 to the same moisture level, and the sample was then added to water and its Brookfield viscosity (spindle No. 1) evaluated as in Example 1 and found to be 32 cps.
In this Example, a further control was provided. No pugging was utilized. Instead, the sample at about 5 to 10% moisture was dry blended with 5% sodium carbonate and otherwise tested as in Example 1, and found to yield a viscosity (No. 3 spindle) of 920 cps.
This constituted a further control. The procedure used was identical to Example 4, except that three passes through the pug mill, each dissipating the mentioned approximate 30 Hp-hr/ton of dry solids, to a total of 9o Hp-hr/ton. The resulting product displayed a Brookfield viscosity (No. 1 spindle) of 16 cps.
The procedure was amenable to Example 3, except for the use of three passes through the pug mill. The measured 3S viscosity (No. 3 spindle) was 1710 cps.
.
' WO9Z/05123 PCT/US91/~8 2~9~78 In this Example, (and in Example 9-11) a different bentonite crude was used than in prior Examples, but still constituting a predominantly calcium bentonite.
The procedure used was the same as in Example 3, and was found to yield a viscosity (No. 1 of spindle) of 152 cps.
The procedure used was identical to that of control Example 4, except the crude was that of Example 8. The resulting viscosity (No. 1 spindle) was measured at 8 cps .
The procedure utilized in this Example was the same as in Example 8, except that 8% sodium carbonate was dry blended into the product from the oven. The resulting viscosity was measured (No. 3 spindle) at 600 cps.
~AMPLE 11 The procedure utilized here was identical to that of Example 9, except that 8~ sodium carbonate was used. The measured viscosity (No. 1 spindle) was 8 cps.
While the present invention has been particularly set forth in terms of specific embodiments thereof, it will be understood in view of the instant disclosure, that numerous variations upon the invention are now enabled to those ski}led in the art, which variations yet reside within the scope of the present teacbing. Accordingly, the invention is to be broadly construed, and limited only by the scope and spirit of the claims now appended hereto.
:
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,
It is common to add water in addition to sodium carbonate to facilitate extrusion. The shearing action disorients the particles and increases the ion exchange. Here the bentonite is not dried and moisture is reduced to approximately 20% after extrusion. 3. The bentonite is first passed through a mechanical kneader, which works the sodium carbonate into the bentonite, and then steam is passed through the clay. The steam, whose low viscosity allows it to penetrate the clay aggregates, will split them and thus allow penetration and ion exchange. In addition the mobility of sodium ions is increased due to the action of the steam, increasing the exchange rate. 4. A
pug mill may also be used, whereby the soda ash is sprinkled onto a field-dried benton~te during its stay on the conveyor belt, with subsequent pugging. Most of the above-listed methods have these parameters in common: they either require time, a large amount of energy, and lots of water, or all three parameters together. The author found that when a bentonite is compacted, while sodium carbonate is simultaneously being added, not only are time and energy saved, but the API properties (viscosity and water loss) appear to improve much more than with the use of traditional ~methods."
45 Lang, U.S. Patent No. 3,700,474 teaches that the crude bentonite clays can be made more readily water disper-sible by compacting the clay which has been previously pulverized. However, no mention is made in either the specification or claims with respect to the need for any drying sequence or addition of alkali or salt.
:
` :
WO92/05123 PCT/US91/~68 2~9~ 80 4 Goodman et al, U.S. 4,483,934 describes a method of beneficiating raw bentonite ore to improve its color.
This involves the alkali treatment of the ore, working, shearing by milling followed by drying of the product.
It should be noted that in all the cases cited above, the prior art employs the use of an alkali or salt treatment as an "activator", either prior to or during the early milling or "working" stage of the sequence. In no in-stance is the addition of alkali considered or describedas being added at the last step of the sequence, such as at "dry-blend", prior to pulverization, and as a matter of fact, such would be highly contrary to the prior art teachings.
Summary of the Invention It has now been unexpectedly found that by shifting the processing sequence from that described in the prior art, we can obtain a significantly enhanced sodium bentonite capable of unusually high solution viscosities.
The sequence that we have discovered unexpectedly represents a total reversal of the state-of-the art pro-cedures and theories. This results in an unanticipatedincrease in the solution viscosity of a solution prepared ; ~ ~ with this inverted bentonite treatment.
The present invention calls for the initial working by shearing of a 20 to 50% water slurry of the crude ore, which has not had any salt treatment. The resultant product is then subsequently dried to about a 5 to 15~
moisture level, preferably to about 5 to 10%, and more preferably to about 5 to 6% moisture. To this dried bentonite material is then added a "bentonite-activating"
metal salt or hydroxide, typical of which is Na,CO,. The dry-blend is then pulverized. The preferred Na,C0, salt '' ., . ~ , WO92/~5123 PCT/US91/~U*
~ 0 91 78 0 is added in the general range of from 3 to 5%, although with certain crudes up to as much as 8% to 10% Na2C0, can be useful.
Although both calcium bentonite and mixtures of calcium bentonite and sodium bentonite can benefit from the invention, it is preferred to use a predominantly calcium bentonite as the starting crude.
In accordance with the foregoing, it may be regarded as an object of the present invention, to provide a process modification which significantly improves (increases) the viscosity characteristics of aqueous bentonite solutions.
It is a further object of the invention to provide a method of upgrading bentonites, particularly calcium bentonites, without the need for any preliminary, lengthy aging/ activation treatment.
Description of the Preferred Embodiment According to a preferred embodiment of this invention, the crude bentonite is initially subjected to shearing in a pug mill. Three or more passes through the milling process are often beneficial, but may not be required for many bentonites, wherein but a single pass confers most of the benefits of the invention. The pug mill can, for example, be of the type desc;ibed in U.S. Patent No.
3,574,345.
The sheared product thus obtained is then dried to a moisture level of about 5 to 6%; although higher levels of moisture can be used, up to 10 to 15%.
The dried product obtained at this stage of the sequence is then dry-blended or mixed with preferably about 3-5%
Na,C0, (in some instances up to about 8-10~ Na2C0, by .
~ , ' ~,' ' '' ~ ' .
W092/05123 PCT/US91/~U~
weight can be beneficial), and the resultant mixture is then pulverized. This is distinguished from the prior art since the Na2C0, salt in this case is added, by simple dry-blending, at the end of the process. The prior art teaches addition of salts such as Na2C0,, either to the ore stage or during the initial milling stage to activate the ore.
According to a further aspect of this invention, the following broad category of bentonite-activator salts and hydroxides will be effective in meeting the objectives of the invention:
Group IA periodic table cations including Na, Li~, ~ and Cs~ in soluble salts and hydroxides, including carbonates and sulfates are considered useful. In Group IIA cations, Mg~ in soluble salt form is useful. The transitional metals, Ni~, Zn~, Cu~ and possibly Co~ are considered useful. The above cations will be available as carbonate and sulfate salts or hydroxides. In specific instances, (NH,),C0" Al,(S0,), and Fe,(S0,), may be useful activators fF certain clays.
The preferred treatment of this invention involves the use of Na,C0" which has been found to give the most bene-ficial results.~ The level of salt addition which has been found to be most effective is broadly between 1~ and 10% based on the weight of bentonite; a preferred range is from 3 to 5% by weight, with the optimum level being about 5%.
Additionally, the embodiment of this invention may also ~include, but is not limited to, the use of an optional dispersing agent during the shearing step, such as tetrasodium pyrophosphate (TSPP) in amounts between about 1-5% by weight of the dry bentonite.
.
.. . .
WO92/05123 PCT/US91/~68 7 209178~
The invention is further illustrated by the following Examples, which are deemed to be illustrative, and not delimitive of the invention otherwise set forth.
A sample of a crude predominantly calcium bentonite clay wet cake containing 35% moisture and 2% tetrasodium pyro-phosphate dispersant was sheared by being subject to one pass through a conventional pug mill, of the type aforementioned. The energy dissipated in the pass through the pug mill was about 30 Hp-hr/ton of dry solids. Upon completion of this working step, the material was dried in a Blue M oven until the moisture content was reduced to about 5%. The sample was then dry blended with 3% Na,CO, and then pulverized. The sample was then added to water such that the solution répresented 5% solids level. Brookfield viscosity data was measured at 30-C using a No. 3 spindle, as llO0 cps.
~!~iL
The processing conditions of Example l were repeated, except that during the pugging step no TSPP was used.
Instead, 2% TSPP, together with 3% sodium carbonate, were ; dry blended with the sample from the oven. The resulting Brookfield viscosity (No. 2 spindle) was 555 cps. (In all of Examples l to 7, the same crude was used.) ExAMpLE 3 ;
The conditions of Example 2 were repeated, except that no TSPP was used and 5% sodium carbonaté was dry blended with the oven dried sample. The ~easured Brookfield viscosity (No. 3 spindle) was 1438 cps.
:
~ , : . , , .: :
"
W092tO5123 PCT/US91/~68 209178~ 8 The procedure in this Example constituted a conventional processing and was a control. Specifically in this instance, a sample of the same crude bentonite clay, as in Example 1, was subjected to one pass through the pug mill in the presence therein of 5% sodium carbonate. The resulting product was dried as in Example 1 to the same moisture level, and the sample was then added to water and its Brookfield viscosity (spindle No. 1) evaluated as in Example 1 and found to be 32 cps.
In this Example, a further control was provided. No pugging was utilized. Instead, the sample at about 5 to 10% moisture was dry blended with 5% sodium carbonate and otherwise tested as in Example 1, and found to yield a viscosity (No. 3 spindle) of 920 cps.
This constituted a further control. The procedure used was identical to Example 4, except that three passes through the pug mill, each dissipating the mentioned approximate 30 Hp-hr/ton of dry solids, to a total of 9o Hp-hr/ton. The resulting product displayed a Brookfield viscosity (No. 1 spindle) of 16 cps.
The procedure was amenable to Example 3, except for the use of three passes through the pug mill. The measured 3S viscosity (No. 3 spindle) was 1710 cps.
.
' WO9Z/05123 PCT/US91/~8 2~9~78 In this Example, (and in Example 9-11) a different bentonite crude was used than in prior Examples, but still constituting a predominantly calcium bentonite.
The procedure used was the same as in Example 3, and was found to yield a viscosity (No. 1 of spindle) of 152 cps.
The procedure used was identical to that of control Example 4, except the crude was that of Example 8. The resulting viscosity (No. 1 spindle) was measured at 8 cps .
The procedure utilized in this Example was the same as in Example 8, except that 8% sodium carbonate was dry blended into the product from the oven. The resulting viscosity was measured (No. 3 spindle) at 600 cps.
~AMPLE 11 The procedure utilized here was identical to that of Example 9, except that 8~ sodium carbonate was used. The measured viscosity (No. 1 spindle) was 8 cps.
While the present invention has been particularly set forth in terms of specific embodiments thereof, it will be understood in view of the instant disclosure, that numerous variations upon the invention are now enabled to those ski}led in the art, which variations yet reside within the scope of the present teacbing. Accordingly, the invention is to be broadly construed, and limited only by the scope and spirit of the claims now appended hereto.
:
' ,:
,
Claims (16)
1. A process for enhancing the aqueous viscosity building characteristics of a bentonite clay; which comprises in sequence the steps of:
(i) subjecting the crude bentonite ore to a shearing step as an aqueous workable slurry;
(ii) drying the product then obtained to a moisture content of 5-15%;
(iii) adding between 1-10% of a bentonite-activating metal salt or hydroxide based on solids as a dry-blend; and (iv) pulverizing the resultant blend into a fine powder.
(i) subjecting the crude bentonite ore to a shearing step as an aqueous workable slurry;
(ii) drying the product then obtained to a moisture content of 5-15%;
(iii) adding between 1-10% of a bentonite-activating metal salt or hydroxide based on solids as a dry-blend; and (iv) pulverizing the resultant blend into a fine powder.
2. The process of claim 1 wherein the bentonite-activating metal salt is selected from one or more members of the group comprising the water soluble carbonates and sulfates of Group IA and Group IIA
periodic table cations.
periodic table cations.
3. The process of claim 1, wherein the product in-step (ii) is dried to about 5 to 6% moisture.
4. The process of claim 1, wherein the salt employed is within the 3 to 5% range based on bentonite solids.
5. The process of claim 4, wherein the salt com-prises sodium carbonate.
6. The process of claim 5, wherein the sodium car-bonate level is 3-8%.
7. The process of claim 6, wherein the sodium car-bonate level is about 5%.
8. The process of claim 1, wherein the bentonite activator is an alkali metal hydroxide.
9. The process of claim 8, wherein the hydroxide is sodium hydroxide.
10. The process of claim 1, wherein the bentonite crude ore is sheared by being subjected to at least one pass through a pug mill.
11. The process of claim 1, wherein the bentonite crude ore is predominantly a calcium bentonite.
12. The process of claim 1, wherein the moisture content upon drying is about 5% in step (ii).
13. The process of claim 1, wherein a chemical dis-persant is present in the wet slurry during the shearing step.
14. The process of claim 13, wherein the dispersant is tetrasodium pyrophosphate (TSPP).
15. The process of claim 14, wherein the TSPP is employed at a 1-5% level based on bentonite solids.
16. The process of claim 13, wherein about 3% of said sodium carbonate and about 2% of said dispersant are added.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US58328890A | 1990-09-17 | 1990-09-17 | |
US583,288 | 1990-09-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2091780A1 true CA2091780A1 (en) | 1992-03-18 |
Family
ID=24332480
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002091780A Abandoned CA2091780A1 (en) | 1990-09-17 | 1991-09-09 | Process for producing bentonite clays exhibiting enhanced solution viscosity properties |
Country Status (8)
Country | Link |
---|---|
EP (1) | EP0549693A4 (en) |
JP (1) | JPH06501444A (en) |
KR (1) | KR930702227A (en) |
BR (1) | BR9106852A (en) |
CA (1) | CA2091780A1 (en) |
MX (1) | MX9101076A (en) |
WO (1) | WO1992005123A1 (en) |
ZA (1) | ZA917398B (en) |
Families Citing this family (7)
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DE19727541A1 (en) * | 1997-06-28 | 1999-01-07 | Sueddeutsche Kalkstickstoff | Solid composition based on clay minerals and their use |
KR100468907B1 (en) * | 2001-12-28 | 2005-02-02 | 김상길 | A binder using Bentonite slurry and it's making method |
JP4632730B2 (en) * | 2004-09-17 | 2011-02-16 | 鹿島建設株式会社 | Seam-proofing material made of bentonite slurry and water-shielding layer forming material |
US20150291477A1 (en) * | 2012-09-28 | 2015-10-15 | Korea Institute Of Energy Research | Method for preparing granulated bentonite formed body and granulated bentonite formed body prepared thereby |
CN103172077A (en) * | 2013-03-18 | 2013-06-26 | 芜湖飞尚非金属材料有限公司 | Preparation method of special trenchless mud bentonite |
EP3498673A1 (en) * | 2017-12-18 | 2019-06-19 | Imertech Sas | Mineral treatment process |
US11447395B2 (en) | 2018-09-28 | 2022-09-20 | King Fahd University Of Petroleum And Minerals | Method of producing sodium bentonite |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2880099A (en) * | 1953-10-14 | 1959-03-31 | Victor Chemical Works | Methods of making clay products and improved clay products |
US3115416A (en) * | 1960-02-09 | 1963-12-24 | Fr Des Glycerines Soc | Method for improving the viscosity of natural clays |
US3106476A (en) * | 1961-04-20 | 1963-10-08 | Huber Corp J M | Method of reducing clay viscosity |
US3509066A (en) * | 1966-10-20 | 1970-04-28 | Engelhard Min & Chem | Attapulgite clay dispersions and preparation thereof |
GB1194866A (en) * | 1967-08-18 | 1970-06-17 | English Clays Lovering Pochin | Improvements in or relating to the Treatment of Particulate Materials |
SU604866A1 (en) * | 1974-06-06 | 1978-04-30 | Всесоюзный научно-исследовательский институт по креплению скважин и буровым растворам | Method of enriching clay for drilling muds |
DD138516A1 (en) * | 1978-08-29 | 1979-11-07 | Werner Tilch | PROCESS FOR THE PREPARATION OF RAW TONES AND RAW BENTONITES |
US4242140A (en) * | 1979-11-28 | 1980-12-30 | International Minerals & Chemical Corp. | Activation of clays by compaction |
-
1991
- 1991-09-09 EP EP19910917187 patent/EP0549693A4/en not_active Withdrawn
- 1991-09-09 KR KR1019930700782A patent/KR930702227A/en not_active Withdrawn
- 1991-09-09 CA CA002091780A patent/CA2091780A1/en not_active Abandoned
- 1991-09-09 BR BR919106852A patent/BR9106852A/en unknown
- 1991-09-09 WO PCT/US1991/006468 patent/WO1992005123A1/en not_active Application Discontinuation
- 1991-09-09 JP JP3515682A patent/JPH06501444A/en active Pending
- 1991-09-13 MX MX9101076A patent/MX9101076A/en unknown
- 1991-09-17 ZA ZA917398A patent/ZA917398B/en unknown
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BR9106852A (en) | 1993-07-06 |
MX9101076A (en) | 1992-05-04 |
WO1992005123A1 (en) | 1992-04-02 |
JPH06501444A (en) | 1994-02-17 |
EP0549693A4 (en) | 1993-10-13 |
KR930702227A (en) | 1993-09-08 |
EP0549693A1 (en) | 1993-07-07 |
ZA917398B (en) | 1992-05-27 |
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