TWI440618B - Cementitious compositions containing feldspar and pozzolanic particulate material, and method of making said composition - Google Patents

Description

Adhesive composition containing feldspar and pozzolanic particulate material and method of making the same Field of invention

The present invention relates to a cementitious composition and a method of making such a composition from a particulate material activated by a feldspar material, which instead uses Portland cement or other materials. The compositions can be used to create fill and backfill materials for a variety of engineering purposes, including underground mine workings, stabilization or solidification of mine waste, and general ground stabilization and paving applications.

Background of the invention

In most cases, the cementitious composition is used for filling, backfilling and stabilization. Specifically, in mines, for safety or other reasons, backfilling operations are often required, or the mine waste at the surface is stabilized or solidified. As a rule of practice, Portland cement is used for this purpose; however, in terms of the high cost of this material and the high cost of transporting it to the desired place of use, worldwide, and especially in Canada, This cost represents the main cost of mining operations. Anything that reduces the amount of Portland cement required will reduce the operating costs of the mine and help to profit from mining operations. Similarly, in other filling and backfilling operations, any practice that reduces the use of Portland cement and that it is replaced by more readily available or cheaper materials will provide a direct financial benefit to the operation.

In the context of mining operations, one material that has recently been found to be potentially used to reduce the amount of Portland cement used is slag, and especially iron-free granular slag, which is smelted copper and A readily available waste product after the nickel concentrate. However, in order to use any material instead of Portland cement, the bond (pozzolanic) properties are essentially equivalent to the cementation properties of Portland cement. Although many forms of slag contain suitable ingredients, it is difficult to activate the slag's bonding properties.

The pozzolanic properties of activated iron-free particulate slag require the addition of a binder supplement as an activator to provide the desired calcium, sulfur and aluminum to form a cementitious mineral ettringite. The ettringite has a primary binder that constitutes Ca ₆ Al ₂ (SO ₄ ) ₃ (OH) ₁₂ × 26H ₂ O and is formed in the cement. In order to form ettringite, calcium is usually supplied from quicklime, sulfur is supplied from gypsum and aluminum is supplied from a supplement of fly ash and calcium aluminate slag obtained by recovering spent catalyst.

Currently, there are three methods for activating iron-free granular slag using conventional methods. The first method is to add a cohesive supplement to the furnace just prior to granulation, such as Philip et al., US 4,756,761 and RJ Atkinson et al. (1989, Using Smelter Slag in Mine Backfill). Slag), Mining Magazine , Vol. 160, No. 8, pp. 118-123). The second method is to blend iron-free granulated slag with Portland cement, as disclosed in US 6,033,467 to Krofchak; however, this method has the drawbacks described above and is activated by the use of Portland cement. Related to the agent. A third method is to add one or more cementitious supplements during mixing with the aggregate material.

For the third method, it is known to use a composition containing fly ash waste as its main component. Fly ash waste can be obtained as a by-product of burning coal in a thermal power plant. However, the use of fly ash as an activator has many deficiencies, including quality issues, transportation issues, and practical issues. Depending on the type of coal from which the fly ash is produced, the pozzolanic properties of the fly ash change, which leads to severe performance inconsistencies and unreliable problems. In some cases, fly ash does not provide a sufficient amount of aluminum for ettring and nucleation of ettringite. In most iron-free furnaces and mining operations, especially in Canada, fly ash is not available locally, so for this application it must be costly to transport.

It is also known to use calcium aluminate to provide aluminum for the nucleation and growth of ettringite. However, the source of such compounds is limited and the cost of transporting them to the desired place of use is very high, or at least significantly increases the cost of the operation.

Accordingly, there is a need for a novel, readily available, and affordable activator to activate a pozzolanic material such as slag to form a cementitious composition that can be used in filling and backfilling operations, particularly Used in place of Portland cement in backfilling underground pits and stabilizing and solidifying the field waste, the cementitious composition does not suffer from many of the drawbacks of known compositions, including the above drawbacks.

It has now been found that feldspar materials can be used as effective and affordable activators for many types of pozzolanic materials, preferably granulated materials, and particularly including slag materials, iron-containing or iron-free. , as well as granular or other forms; and also include fly ash and enamel rock with the worst self-bonding properties.

Summary of invention

The present invention seeks to provide a combination of a cementitious composition and a feldspar-activated pozzolanic material, wherein the pozzolanic material replaces the use of Portland cement to provide suitable filling and backfilling operations, particularly for backfilling. Underground pits and compositions that stabilize/solidify the mine waste.

Feldspar is a type of rock-forming mineral that forms the bulk of the earth's crust. Feldspar consists of two major mineral systems, alkaline feldspar and plagioclase feldspar. The difference between alkaline feldspar and plagioclase is complicated by the solid solution phenomenon. Alkaline feldspar is a monoclinic or triclinic crystal with a higher potassium content than calcium. The plagioclase is a triclinic crystal whose potassium content is lower than that of calcium or sodium. The plagioclase is formed from a continuous series of sodium citrate aluminum and calcium aluminum silicate. The sodium endmember in the plagioclase is albite and the calcium endmember is anorthite. The intervening members are aragonite, medium feldspar, labradorite and albite. The most ubiquitous members are albite and labradorite. The plagioclase is found in almost all igneous and metamorphic rocks and is associated with copper-nickel mining/melting operations in Canada and other parts of the world. Alkaline feldspar is mainly composed of Orthodox feldspar and Micro plagioclase. The syenite series has a monoclinic crystal and the micro plagioclase series has a slant crystal. Alkaline feldspar is a very common mineral and in Canada and other parts of the world, alkaline feldspar is present in surrounding rock such as granite or pegmatite granite at or near mining operations/melting operations.

The plagioclase and alkaline feldspar are good sources of bismuth and aluminum required for the nucleation and growth of ettringite. The calcium compound such as calcium oxide is used to increase the pH of the feldspar to the alkalinity level required to activate the aluminum component of the feldspar.

The use of feldspar to activate a pozzolanic material has many advantages over current activation methods, particularly when it relates to the desired end use for mining operations. The plagioclase is readily available for many applications because they naturally exist in a wide range. Specifically, they occur adjacent to mining operations and smelting operations, and thus do not require cost and time to transport to the mine over long distances. In addition, feldspar does not have the known drawbacks of Portland cement (high price) or fly ash (variable composition and varying pozzolanic properties, unreliable supply, transportation costs).

The use of feldspars, including alkaline feldspars, especially micro plagioclase, and each plagioclase as a pozzolanic activator has been found to provide consistent and improved results over the use of fly ash, and adds many advantages, namely these materials Easy to obtain, usually adjacent to where it is intended to be used, and significantly more economical than known materials, while providing both direct and indirect environmental benefits.

It has further been found that these feldspars effectively activate the pozzolanic properties of a variety of materials. As noted above, these materials include iron-containing and iron-free slag in particulate form prepared by granulation or air cooling. Other materials that may be activated by the selected feldspar include those types of fly ash that have the worst self-bonding properties or have no self-bonding properties; those of the enamel, particularly those comprising at least one of calcium, magnesium, sodium, and aluminum. Most especially the mafic rock.

According to a first broad aspect, the present invention seeks to provide a method of making a cementitious composition comprising the steps of:

(a) selecting at least one pozzolanic particulate material;

(b) selecting at least one feldspar material and grinding it to a fineness of at least 3,000 Blaine;

(c) mixing a lime compound selected from the group consisting of calcium oxide and calcium hydroxide with gypsum;

(d) mixing the ground material in step (b) with the mixture in step (c) to form an activator mixture;

(e) adjusting the pozzolanic particulate material in step (a) by mixing in a gradually added aqueous solution;

(f) adding the activator in the step (d) to the conditioning product in the step (e), and then stirring the mixture to form a slurry;

(g) curing the slurry of step (f) in a sealed container.

The pozzolanic particulate material may be selected from the group consisting of at least one slag material, at least one enamel rock, fly ash, and combinations thereof. If a slag material is used, it is preferably ground to a fineness of at least 3000 Bran, more preferably 3400 Bran and may comprise at least one particulate slag material, at least one non-granular slag produced by an air cooling process Material or a combination of particulate material and non-particulate material.

Similarly, if the pozzolanic particulate material is enamel, it is preferably ground to a fineness of at least 3,000 bland, more preferably 3,400 blan. The rock material preferably comprises at least one of calcium, magnesium, sodium and aluminum, and more preferably comprises at least 2% by weight of such mineral.

Preferably, the aqueous solution is a lime saturated solution, and if a slag material is used, it may be iron-free or iron-containing.

The feldspar material may be at least one of plagioclase and alkaline feldspar, or a combination of plagioclase and alkaline feldspar; preferably, plagioclase is selected from the group consisting of albite, aragonite, mesquite, labradorite, anorthite, and combinations thereof. And the alkali feldspar is preferably a micro plagioclase.

Preferably, the conditioning is carried out during a period of between 5 minutes and 24 hours, and at a temperature of at least 10 ° C, preferably between 10 ° C and 100 ° C, more preferably between 10 ° C and 50 ° C. An aqueous solution is added over a period of time between 5 minutes and 24 hours.

Preferably, the addition activation is carried out at a temperature in the range of at least 10 ° C, preferably between 10 ° C and 100 ° C, more preferably in the range of 10 ° C to 50 ° C, for a period of 5 minutes to 6 hours. The steps of the agent.

Preferably, the step of curing the slurry is carried out for a period of at least 28 days.

According to a second broad aspect, the present invention seeks to provide a cementitious composition comprising a pozzolanic particulate material, a ground feldspar material, a lime compound selected from the group consisting of calcium oxide and calcium hydroxide, and gypsum.

Corresponding to the method of the invention described above, the pozzolanic particulate material for the composition may be selected from the group consisting of at least one slag material, at least one enamel rock, fly ash, and combinations thereof. If a slag material is used, it is preferably ground to a fineness of at least 3000 Bran, more preferably 3400 Bran and may comprise at least one particulate slag material, at least one non-granular slag produced by an air cooling process Material or a combination of particulate material and non-particulate material. If fly ash is used, it can be activated without first grinding.

Similarly, if the pozzolanic particulate material is enamel, it is preferably ground to a fineness of at least 3,000 bland, more preferably 3,400 blan. The rock material preferably comprises at least one of calcium, magnesium, sodium and aluminum, and more preferably comprises at least 2% by weight of such mineral.

Preferably, the cementitious composition further comprises an aqueous solution; more preferably, the aqueous solution is a lime saturated solution. If a slag material is used, it may be iron-free or ferrous, and may include at least one particulate slag material, at least one non-granular slag material or particulate material produced by an air cooling process, and A combination of granular materials.

The feldspar material may be at least one of plagioclase and alkaline feldspar, or a combination of plagioclase and alkaline feldspar; preferably, plagioclase is selected from the group consisting of albite, aragonite, mesquite, labradorite, anorthite, and combinations thereof. And the alkali feldspar is preferably a micro plagioclase.

According to a third broad aspect, the present invention seeks to provide a cementitious composition prepared by the method of the present invention.

Detailed description of the preferred embodiment

In the broadest aspect of the invention, the method of the invention for making a cementitious composition from a feldspar-activated pozzolanic particulate material comprises the following steps.

First, a suitable pozzolanic particulate material that can be utilized is selected, and if a fineness of at least 3000 Bran is desired, the pozzolanic particulate material is also prepared. In the case of slag materials or shale materials, these materials are ground to the required fineness; fly ash can generally be used without being ground or otherwise prepared. As noted above, if a slag material is used, it may be particulate or non-granular as produced by an air cooling process, or may be a combination of particulate and non-particulate materials. The slag material may be an iron-free slag material or at least one iron-containing slag material.

Next, at least one feldspar material is selected and ground to a fineness of at least 3000 Bran. The feldspar material is preferably at least one of plagioclase and alkaline feldspar. The plagioclase is preferably albite, aragonite, medium feldspar, labradorite, anorthite, and combinations thereof. The alkaline (alkalki) feldspar is preferably a micro plagioclase.

An activator mixture is prepared by mixing calcium oxide or calcium hydroxide, preferably calcium oxide, with gypsum, and then mixing them in the ground feldspar; in this activator mixture, calcium oxide or calcium hydroxide provides calcium And the gypsum provides the required sulfur, and the aluminum in the milled feldspar is used for calcification and growth of the ettringite.

The ground slag material is then adjusted by gradually adding an aqueous solution. A lime saturated solution was found to be a particularly effective aqueous solution. Preferably, the conditioning is carried out over a period of time between 5 minutes and 24 hours, at a temperature in the range of at least 10 ° C, preferably between 10 ° C and 100 ° C, more preferably in the range of 10 ° C to 50 ° C, An aqueous solution is added over a period of between 4 hours and 24 hours.

Next, the activator mixture is added to the conditioned milled material and the mixture is allowed to stir to form a slurry. Preferably, this step is carried out in a period of from 5 minutes to 6 hours at a temperature in the range of at least 10 ° C, preferably between 10 ° C and 100 ° C, more preferably in the range of 10 ° C to 50 ° C. . Thereafter, the slurry is cured by known methods, and thereafter, the slurry is subjected to testing by known methods and then used for its intended end use for filling, backfilling, paving or the like, including at the mine. Backfilling, stabilizing or solidifying the field waste material in the same manner as prior art cementitious materials.

Claims (30)

A method of making a cementitious composition substantially free of Portland cement, comprising the steps of: (a) selecting at least one of the at least one slag material, at least one shale rock, fly ash, and combinations thereof a particulate material; (b) selecting at least one feldspar material and grinding it to a fineness of at least 3,000 blan; (c) mixing a lime compound selected from the group consisting of calcium oxide and calcium hydroxide with gypsum; (d) step (b) The ground material in the mixture is mixed with the mixture in step (c) to form an activator mixture; (e) the hardenable particulate material in step (a) is adjusted by mixing in a gradually added aqueous solution to produce a Adjusting the product; (f) adding the activator in step (d) to the conditioning product in step (e), then agitating the mixture to form a slurry; and (g) curing step (f) in a sealed container The slurry in. The method of producing a cementitious composition according to claim 1, wherein the at least one pozzolanic particulate material comprises at least one slag material, and the step (a) further comprises grinding the at least one slag material to at least 3000 Bran's fineness. The method of producing a cementitious composition according to claim 1, wherein the at least one pozzolanic particulate material comprises at least one shale rock, and the step (a) further comprises grinding the at least one shale rock to at least 3000 Bran's fineness. The method of producing a cemented composition according to claim 1 or claim 2, wherein the at least one slag material is selected from at least one particulate slag material, at least one produced by an air cooling process Slag material and combinations thereof. The method of producing a cementitious composition according to the first aspect of the invention, wherein the at least one enamel rock comprises at least one of calcium, magnesium, sodium and aluminum. The method of producing a cementitious composition according to claim 5, wherein the at least one enamel rock comprises at least 2% by weight of at least one of calcium, magnesium, sodium and aluminum. The method of producing a cementitious composition according to any one of claims 1 to 3, wherein the aqueous solution is a lime saturated solution. The method of producing a cementitious composition according to claim 1, wherein the selecting step in the step (b) comprises selecting at least one of plagioclase and alkaline feldspar. The method of producing a cementitious composition according to claim 8, wherein the selecting step in the step (b) comprises selecting at least from albite, aragonite, mesquite, labradorite, anorthite, and combinations thereof. An plagioclase material. A method of producing a cementitious composition according to the invention of claim 8 or claim 9, wherein the alkaline feldspar is a micro plagioclase. The method of producing a cementitious composition according to any one of claims 1-3, wherein the at least one slag material is an iron-free slag material. The method of producing a cementitious composition according to any one of claims 1-3, wherein the at least one slag material is an iron-containing slag material. The method for producing a viscous composition according to claim 1, wherein the adjusting step in the step (e) is carried out in a period of between 5 minutes and 24 hours, and the aqueous solution is a lime saturated solution. And is added at a temperature of at least 10 ° C for a period of between 4 hours and 24 hours. The method for producing a cemented composition according to claim 13, wherein the lime saturated solution is added at a temperature ranging between 10 ° C and 100 ° C. The method of producing a cemented composition according to claim 14, wherein the lime saturated solution is added at a temperature ranging between 10 ° C and 50 ° C. The method of producing a viscous composition according to claim 1, wherein the step (f) is carried out at a temperature of at least 10 ° C for a period of between 5 minutes and 6 hours. The method of producing a viscous composition according to claim 16, wherein the step (f) is carried out at a temperature in the range between 10 ° C and 100 ° C. The method of producing a cemented composition according to claim 17, wherein the step (f) is carried out at a temperature in the range between 10 ° C and 50 ° C. The party for producing a cementitious composition according to claim 1 of the patent application scope The method wherein step (g) is carried out over a period of at least 28 days. A cementitious composition substantially free of Portland cement comprising at least one pozzolanic particulate material selected from at least one slag material, at least one smectite, fly ash, and combinations thereof, together with ground A feldspar material, a lime compound selected from the group consisting of calcium oxide and calcium hydroxide, gypsum, and an aqueous solution containing a saturated lime solution. The adhesive composition of claim 20, wherein the at least one pozzolanic particulate material comprises at least one slag material ground to a fineness of at least 3000 Bran. The adhesive composition of claim 20, wherein the at least one pozzolanic particulate material comprises at least one enamel rock ground to a fineness of at least 3,000 Bran. The adhesive composition according to claim 22, wherein the at least one enamel rock comprises at least one of calcium, magnesium, sodium and aluminum. The adhesive composition according to claim 23, wherein the at least one enamel rock comprises at least 2% by weight of at least one of calcium, magnesium, sodium and aluminum. The adhesive composition according to claim 21, wherein the ground slag material is selected from the group consisting of at least one granular slag, at least one slag material produced by an air cooling process, and combinations thereof. . The adhesive composition according to any one of claims 20 to 25, wherein the ground feldspar material is selected from the group consisting of at least one of plagioclase and alkaline feldspar. The adhesive composition according to claim 26, wherein the plagioclase is selected from the group consisting of albite, aragonite, mesquite, labradorite, anorthite, and combinations thereof. The adhesive composition according to claim 26, wherein the alkaline feldspar is a micro plagioclase. The adhesive composition according to claim 21 or claim 25, wherein the ground slag material is an iron-free slag material. The adhesive composition according to claim 21 or claim 25, wherein the ground slag material is an iron-containing slag material.