CA2235526C - High pulp density fast setting and high early strength backfill method and material - Google Patents
High pulp density fast setting and high early strength backfill method and material Download PDFInfo
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- CA2235526C CA2235526C CA 2235526 CA2235526A CA2235526C CA 2235526 C CA2235526 C CA 2235526C CA 2235526 CA2235526 CA 2235526 CA 2235526 A CA2235526 A CA 2235526A CA 2235526 C CA2235526 C CA 2235526C
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- 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
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
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- 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
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
- C04B28/06—Aluminous cements
- C04B28/065—Calcium aluminosulfate cements, e.g. cements hydrating into ettringite
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- 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
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00034—Physico-chemical characteristics of the mixtures
- C04B2111/00146—Sprayable or pumpable mixtures
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- 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
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/00724—Uses not provided for elsewhere in C04B2111/00 in mining operations, e.g. for backfilling; in making tunnels or galleries
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- 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
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Soil Conditioners And Soil-Stabilizing Materials (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
This invention discloses a high pulp density, fast setting and high early strength backfill method for underground mining, in which novel binding materials, with high early strength properties, are used as the binding reagent, where mine tailings, natural sands, ground sands and industrial waste materials are used as aggregate. The binding material, aggregate and water are mixed together uniformly to produce a high pulp density backfill slurry with 65 - 85% pulp densities. The backfill slurry produced is transported to underground mining stopes through a pipeline by gravity or pumping.
Once the backfill slurry fills the stope, it quickly solidifies within several hours into a solid backfill body with high early strength. One obvious advantage of the present invention, compared with the traditional backfill methods using Portland cement as binding material, is that one tonne of the novel material obtains the same compressive strength as threes tonnes of Portland cement as binding material. Another important property of the present backfill materials and methods is that the curing time for the backfill body will be decreased from 7 - 28 days to 1 - 3 days, which can significantly decrease the operation cycle time for underground mining and increase efficiency.
Because of the very good early strength and homogeneous backfill body, better working conditions and improved safety in mining operations are achieved. Further, because of the large amount of mine tailing being used as aggregates without classification, the surface pollution in mines is decreased. The new methods disclosed in this invention may be combined with various mining methods to form upward backfill, downward backfill, partial backfill, complete backfill and other types of backfill, to be used in diverse mining conditions.
Once the backfill slurry fills the stope, it quickly solidifies within several hours into a solid backfill body with high early strength. One obvious advantage of the present invention, compared with the traditional backfill methods using Portland cement as binding material, is that one tonne of the novel material obtains the same compressive strength as threes tonnes of Portland cement as binding material. Another important property of the present backfill materials and methods is that the curing time for the backfill body will be decreased from 7 - 28 days to 1 - 3 days, which can significantly decrease the operation cycle time for underground mining and increase efficiency.
Because of the very good early strength and homogeneous backfill body, better working conditions and improved safety in mining operations are achieved. Further, because of the large amount of mine tailing being used as aggregates without classification, the surface pollution in mines is decreased. The new methods disclosed in this invention may be combined with various mining methods to form upward backfill, downward backfill, partial backfill, complete backfill and other types of backfill, to be used in diverse mining conditions.
Description
CA 0223.7.726 1 998 - 04 - 22 HIGH PU-LP DENSITY FAST SEl~I'ING AND HIGH EARlY STI~EN~TH
E~ACKFILL METHC~I) AND MAIERlAL
BACKGROUNl~ OF THE INVENTION
1. Field ol~ the Invention S The present invention is directed to method and mater~al tor undergl~und mine bachC"ill with high pulp density fast setting and high early strength backfill. More particularly, it is directed to high crystal water content, fast setting and high early strength binding material which is mixed with mine tailings, sands, ground sands, industrial solid waste materials, or their mixture, a~d water to make a high pulp density back~ll slurry with 10 65 - 85~ pulp density. More particularly still, the slurry is then sent to the mine stope through a pipeline either by gravity or by pumping. The backfill slurry in the stope solidifies quickly to form a backfill body wi~ high early streng~. The backfill body reaches more ~an 70% of its final strength in about 12 to 72 hours The present backfill method may be widely usçd i~or upwards, downwards, and other mining 15 applications.
E~ACKFILL METHC~I) AND MAIERlAL
BACKGROUNl~ OF THE INVENTION
1. Field ol~ the Invention S The present invention is directed to method and mater~al tor undergl~und mine bachC"ill with high pulp density fast setting and high early strength backfill. More particularly, it is directed to high crystal water content, fast setting and high early strength binding material which is mixed with mine tailings, sands, ground sands, industrial solid waste materials, or their mixture, a~d water to make a high pulp density back~ll slurry with 10 65 - 85~ pulp density. More particularly still, the slurry is then sent to the mine stope through a pipeline either by gravity or by pumping. The backfill slurry in the stope solidifies quickly to form a backfill body wi~ high early streng~. The backfill body reaches more ~an 70% of its final strength in about 12 to 72 hours The present backfill method may be widely usçd i~or upwards, downwards, and other mining 15 applications.
2. Prior Art As presently practised around the world, an important problem of using Portland cement as binding material for mine backfill is to reconcile the requirements of backfill body strength and the requirement tor transportation of the backfill slurry.
In order to increase the backfill body strength, the ratio of water to cement has to be S low on the one hand, but on other hand, to increase tlowability of the backfill slurry, much more water has to be used. The typical water to cement ratio is between 0.3 and 0.6 for Portland cement in order to get proper hydration, which is a relatively small ratio of water needed for hydration. But in order to meet the re~luirc,llc--~ for slurry transportation, pulp density of the slurry has to be less than 65 - 70%, to mal~e 10 it easily transportable to the mine stope through a pipeline. The excess amount of water in the backFIll slurry will have to be removed in the stope. Coarse aggregate~s such as s~nds, ground sands of coarse fractions from tailings are usually used in order to make dewatering easier. In addition to this problem, the cement backfill body takes 7 - 28 days to reach the required strength. As a result, a long waiting period is 15 necessary in order to continue mining the ores beside the backt~llled body. The cyc1e of drilling, blasting, ore transportation and backfill is prolonged.
There are other problems facing existing and tra lition~l Portland cement backflll methods:
1. A large amount of cement in the slurry is carried away by water during the 20 dewal~ling process. This not only causes ellv~n~ nt~l problems, but also decreases the strength of the backfill body.
2. Large spaces between the back~lll body and the roof of the stope cannot be fully filled due to slurry volume loss during dewdle~ g. Multip1e backfilling procedures are often require~ to fill up this space.
5 3. In order to create high permeability in the bacl~fiM body, only the coarse fractions of the tailings can be used as aggregate. Tailing utilizatioD effciency is therefore low, at less than 40~. The large quantity of unused fme tailings has to be disposed of on land at the surface, which causes e.lYilollnlelllal problems on mine surfaces.
10 4. The making of groun~ sands or purchase of sands to make up aggregates is costly, if the arnount of tailings available is not sufficient for backfilll.
5. Due to the long solîdifying period of the bacln~ill body of between 7 and 28 days, means delay before the next mining operation may begin, thus production efficiency is lowered.
15 In order to solve the technical problems listed a~ove, some mines have tried paste backfill. The binding material is still Portland cement, but the pulp density of the slurry has to be increased to more than 80%. Less water needs to be removed from this paste slurry in the mine stope. As a result, the strength of the backfil1 body increa~ses. However, due to the poor flow characteristics of the pa~ste, it raises a lot of transportation problems and it can only be used in large vertical height mines where gravity flow is used. Special mixing equipment such as 'double axis mixers' have to S be used for mixing and special positive displacement pumps for paste slurry transportation are required. The main problem~s associated with this method are: ~a) A pressure filter is required for making paste~ where capita1 cost is high and the process is complex, ~b~ Pipeline blockage occurs quite often due to too high pulp density, so that the paste slu~g transportation through a pipeline is very difflcult; (c) 10 Both curing periods and operation cycles of mining are too long, since Portland cement is used as the binding material; (d) Operating costs are high due to high cement consumption; (e3 It is difficult to fill up all of the space in a stope, because of the poor flow characteristics of the paste.
In order to solve the above problems, research on new binding materials and low pulp 15 density backfill methods have made progress in China. Chinese patents ZL90 103141.0 and ZL91 103829.9, to Henghu Sun et al., have disclosed a new process for metal mine backfill. These processes use so-called 'high water content' materials to replace Portland cement as binder to form a low pulp density slurry with 15 - 70%
pulp density. The "high water content" material binder is made of two equal parts 20 termed A and B materials. Both slurry A cont~ining the A binding material and s1urry B co~ -g the B binding material are sent to the mine stope through two separate CA 0223.7.726 1 998 - 04 - 22 pipe1ines. The two slurries are then mixed together at a place close to the mine stope for backfill. After 30 minutes7 the bacl~lll slurry solidifies in the stope without lusing any water.
However, there are some problems associated with this method: (i) The ratio between S A and B has to be exactly at one. Ch:lngin~ of this ratio may prevent the slurry from solidifying; (ii) The A and B slurries have to be transported through two separate pipelines. This directly increases the capital cost of the mining process; (iii) Since the two slurries have to be mixed at a place close to the backfill stope in the mine, s~ti~f~tory mixing requires that the pulp density of the slur~g must be less than 70%;
10 (iv) Due to the low solids content in the slurry, more hinder material is needed it high strength is required. This increases the cost of the hackflll.
United States Patent No. 5,141,365 issued August 25, 1992 to Smart discloses that a void in a mine is hackfilled by a backfill slurry comprising water, an inert filler, e.g.
mine tailings, and a binder, e.g. cement, lime or slag, to which a gelling agent, e.g.
15 sodium silicate, is added just before placement. The salient feature of this patent is that the bachSII slurry is made of tailings, water, Portland cement7 lime and slag.
United States Patent No. 4,101,333 issued July 18, 1978 to Wayment discloses a me~hod of ~ac~lling in underground mine operations by a mill tailings slurry which is dewatered to provide a material with a controller water content to permit the dewatered material to be used as a backfill witnout requiring any substantial dewatermg after placement and which material can, when desired, be mixed with selected quantities of cement to provide a mortar for ba~ llin~ or surt'ace covering.
The salient feature of this patent is using de-watered tailings for mine backfill The S dewatering of the backfi11 slurry underground in the mine is not necçss:lry. Port1and cement is mixed with prepared backfill aggregate to make a backfill slurry.
Both of tne aboYe two Unite~ States patents use Portland cement as binding material, and have the common disadvantage discussed above.
United States Patent No. 5,340,235 issued August 23, 1994 to Milliken discloses a 10 method for hydraulically b?,~filling empty mined salt cavities. The method comprises combining at least one pozzolanically active waste material with an effective amount of an ~lk~line earth metal in the form of an ~ lin~ earth metal hydroxide or jqlk~lin~
earth metal oxide and saturated brine to form a pozzolanic mixture, wherein the relative proportion,s of said po~zolanically active waste material, ~lk~ earth metal 15 hydroxide or ~lk~line earth metal oxide and sdluldled brine are sufficient for reaction under atmosphere conditions in said salt cavity to form a stable, low porosity, load bearing pozzolanic cement; and hydraulically depositing said pozzolanic ~ ure in the empty salt cavity United States Patent No. 5,464,473 is~sued November 7, 1995 to Shiao discloses a CA 0223.7.726 1998 - 04 - 22 backfill for an engineered barrier used to contain radinactive waste has a predel~ ined amount of clayic material and a predelel ~I~ined amount of a rein~olcement material with hydrophobic surface cl~lac~eristics. The reinforcement material may include hydrophobic compounds selected from group con~i~tin~ of S organic polymers or inorganic materials on which a 1ayer of hydrophobic compounds is formed. The hydrophobic reillforcement material results in the backfill ~ i"f~in;l~g a very low water permeability while providing high mechanical strength and other properties suitable for use in a repository of radioactive waste.
United States Patent No. 4,059,963 issued November 29, 1977 to Wayment discloses 10 a method of backfilling in underground mine operations by a mill tailings slurry which is dewatered to provide a material with a controlled water content to permit the dewatered m~t~ l to be used as a bacffill without requiring any subs~lial dewa~ g after placement and which material can, when desired, be mixed with selected quantities of cement to provide a mortar for ba~lrfilling or surface covering.
United States Patent No. 4,746,249 issued May 24, 1988 to Haigh et al. discloses an a4ueous slurry of backfill material e.g. slimes, includes a settable ttl~eri~l and an activator therefor, e.g. pulverized fuel ash and lime, and a lubricant e.g. clay and a plasticizer, e.g. a lignosulphonate so that the slurry can be pumped over long distances but will then set to develop high early strength.
United States Patent No. 5,106,422 issued April 21, 1992 to Bennett et al. discloses a rapid-setting self-hardening backfill composition and a method of in~t~ tion. The composition comprising a minor amount of Class C fly ash as a primary constituent and other filler m~teri~l~ such as Class F fly ash in major amount. When such 5 materia1s are combined with water in control1ed amount, they produce a backfilling material which is flowable and self-leveling for easy in~t~ tion in utility trenches and simi1ar excavations in street and roadway surfaces to support re1atively heavy co~ essive 10ads within relatively short periods of time without settling. The self-hardening ini~al1y flowable ~ ures attain considerable strength for withst~n-~in~
10 traffilc loads without undue settling in time periods of about 4 hours. The rapid-setting of the composition provides a rapidly ~t~in~l~le strength of the order of about 20 psi within about 4 hours to permit overlaying a wearing course of paving material and reopening of excavated areas of streets and roadways without undue traffic delays and congestion. The bac~fillin~ composition ranges in amount from about 2 to 10 parts 15 by weight filler material to about 1 part by weight Class C fly ash with suffilcient water to react with both Class C fly ash and filler material. The composition utilizes by-products of coal-fired power stations to form a most economic b~ llling material and method of utilization to provide both early strength and precisely controlled pe~lllanent strength to permit ready reexcavation.
20 Other patents disclosin~ new binder materials for mine backfill are: United States Patent No. 4,992,103, titled Cc.. ~ us Composition; United States Patent No.
CA 0223.7.726 1 998 - 04 - 22 4,798,628 titled Apparatus Delivering a Rapidly Setting Composition; and European Patent No. 286~9, titled Rapid set composition.
The major differences among the above patents are that different binders are used.
In some, binder consumption is very high at 300 - 500 kg per cubic metre. This is 5 only used for special cases in coal mines due to high cost.
SUMMARY OF THE INVENTJON
The present invention endeavours to solve the problems described above. Salient features of the method of the present invention are:
- Increase of tne backfill slurr,v pulp density to 65 - 85%.
10 - Use of all types of tailings, natural sands, ground sands and industrial solid waste materials as aggregates.
- Use of various proportions of basic binding materials, accelerating reagents, r~lardillg reagents, and suspension reagents to adjust the backfill slurry setting speed, ~setting time, early strength, flow characteristics and transportation.
15 - Alteration of binder addition procedures and slurry making procedures to obtain the required results.
- Large quantities of tailings and industrial solid wastes can be used for mine backfill.
- The making of high pulp density backfill slurry, such that underground de-watering is not required in some cases.
- Existing backfill technology can be used for various mine conditions through adjusting of the present method of making the present binding material composition, and the method of producing the new backfill slurry and its tran.~portation procedures.
10 Using the backfill technology of the present invention, full tailings from a mine mill can be used as aggregates. In prior methods, when using Portland cement as binder, the tailings must be classified to remove fine tailings; only about 40% of the tailings with particle si~s larger than 37 microns can be used as aggregates. In the present backfill technology, all tailings without classification can be used for backfill. R~Ckfill 15 slurry may be made by mixing any kind of tailings with water to make a slurry with 65 - ~5% pulp density by weight. It is then sent to the mine stope through one pipeline rather than two pipelines. The weight of the present binding material added to the backfill slurry is between 0.5 and 20% by weight. If there are no tailings available for bacffill, natural sands, ground sands, industrial solid waste materials or a mixture of thereof may be u~sed as aggregates. The natural sands include river sands, ~sea sands, sands from mwnlai~s. The ground sands are made from grinding rock into particle sizes of 0.04 - 5 mm. The industrial solid waste mq~ could be S iron smelter slag, power plant slag and various industrial waste slags.
According to the present invention, there is provided a high pulp density fast setting and high early strength backtill material and method for use in undergfoulld mines COII~hiSillg: one part of mine tailings, natural sands, ground sands, and solid industrial waste materials as aggre~ate; a binding material of between O.S and 20% by weight 10 mixed with water to form a slurry with 65 - 85% pulp density by weight; and transporting the slurry to the stope of a mine through a single pipeline.
Preferably, the present binding material is composed of six groups of components in the following ratios:
Component 1 can be one of, or a ~ e of sulpho-ah~ e cement clinkers, ferro-15 ~lumin~t~ cement clinkers, fluo~ e cement clinkers and high ~hlmin:~t~ cementclinkers, in any ratio. The concentration of component 1 in the binding material is between 40 - 90% by weight~ pl~rel~ly at 45 - 80% by weight and best at 50 - 70%
hy weight.
Component 2 can be one of, or a mixture of anhydrite and gypsum, in any ratio. The concentration of component 2 in the binding material is between 5 - 50% by weight, prerelably at 10 - 40% by weight and best at 15 - 40% by weight.
Component 3 can be one of, or a mixture of lime and hydroxide lime in any ratio.
5 The concentration of component 3 in the binding material is up to 30% by weight, preferably at 3 - 25% by weight and best at 5 - 20% by weight.
Component 4 can be one of, or a mixture of KCI, NaCI, CaC12, MgC12, ZnCI2, Na2C03t K2C03, Li2C0~, Li cc,..l~inii.g chemical compounds, Na2S04, K2S04, A12~S04)3, Na2S203, Na~, Na3P04, NaN03, K1~03, all alkalis, triethanolamine, 10 tri-isopropanolamine, c~balllide, in any ratio. The concentration of component 4 in the binding material is up to ~0 by weight, preferably at 0.05 - 6% by weight and best at 0.2 - 5% by weight. Component 4 is used as accelerating or/and high early strength reagent.
Component S can be one, or a llli~lule of sugars, molasses, lignosulphonates, tartaric 15 acid, tartrates salts, citric acid, citrate salts, boric acid and borate salt, in any ratio.
The concentration of component S in the binding material is up to 2% by weight, preferably at 0.05 - 1% by weight and best at 0.1 - 1% by weight. Comp~nent S is used as rel~ding or/and dispersion reagent.
Component 6 can be one of, or a ~ ur~ of bentl-nite, lime~stone, tlyash, silica fume, slag powder, cement, talc powder, clay powder, baux~te powder, anhydrite, gypsum, lime and hydroxide lime, in any ratio. The concentration of component 6 in the binding material is up to 31)% by weight, preferably at 0.1 - 10% by weight and best 5 at 0.5 - 5% by weight.
In another aspect of the present invention, there is provided a me~hod for producing a binding material for high pulp density, fast setting, high early strength b~
comprising: mixing of the above six groups of components in preselected ratios; an~
making and grinding the components to pass 100 Tyler mesh. P~ bly, the ratios 10 of the six components are:
(a) component 1: 45% - 80% by weight;
(b~ component 2: 10 - 40% by weight, (c~ component 3: 3 - 25% by weight;
~ d) component 4: 0.05 - 6% by weight, whereby component 4 is used as 15 accelerator or/and high early strength reagent;
(e~ component S: 0.1)5 - 1% by weight, wheleby component 5 is used as re~der or/and dispersion reagent; and ~f) component 6: 0.1 - 10% by weight.
In yet another aspect, the me~od of making high pulp density, fast setting and high early strength backfill slurry for underground backfill comprises using one of, or a 5 mixture of mine tailings, natural sands, ground sands and industrial solid waste materials at any ratio as backfill aggregate; mixing the backfill aggregate, water and material together uniformly to make a slurry with pulp density of 65 - 85 % by weight;
and transporting the slurry to the mine stope through a single pipeline by l~u114~illg or by gravity; wherein the ratio of the binding material to the backfil1 aggregate is between 1:5 and 1: 100 by weight.
A preferred method for prep~on of high pulp density7 fast setting and high early strength backfill slurry comprises the fol10wing steps: mixing one of, or a mixture of mine tailings7 natural sands, ground sands and industrial solid waste m~terial~7 in any ratio7 with water to form a homogenous and uniform sand slurry with a pulp 15 density of 63 - 82% by weight; adding binding material to the sand slurry through a feeder and mixing the slurry for 2 - 8 mim~tes in a ~ ur~ to form a backfill slurry with pulp density of 65 - 85% by weight; wherein the ratio of the newly invented binding material added to the backfill slurry is from 1:5 to 1:100 by weight7 and tran~sporting the bacloSII slurry to the stope in the mines through a pipeline by pumping or by gravity.
In another aspect, the ~ ~d~ion of high pulp density, fast setting and high early strength backfill slurry for underground backfi11 comprises the following steps: mixing one of, or a mixture of mine tailings, natural sands, ground sands or industrial solid S waste materials, in any rativ, with water to torm a homogenous and uniform sand slurry with a pulp density of 63 - 82% by weight; transporting the sand slurry to a site close to the stope in the mine through a pipeline by pumping or by gravity, at which site, adding binding material to the sand slurry inside the pipeline through a feeder, wherein the binding material added is well-mixed with the sand slurry through a 10 turbulent flow pattern inside the pipeline on its way to the stope; and wherein the formed backf111 slurry has a pulp density of 65 - 85 ~ by weight, and the ratio of the binding material added to the backfill slurry is from 1:5 to I:100 by weight.
Another method of providing binding material comprises: mixing components 1, 2 and 3 as defined above to form another component 7 as a binding material, wherein the 15 c(J-Ice~ alion by weight of each component in the binding material is as follows:
component 1 40 - 90%; component 2 5 - 50%; component 3 3 - 30%; grin~ling the component 7 to pass tOO Tyler mesh; mixing cvmponent 4 with component 6 in a ratio of 1 to up to 5 by weight, then grinding the l~ ure to pa~ss 70 Tyler mesh and packaging the result separately to form (accelerating reagent) component 8; mixing 2() component 5 with component 6 in a ratio of 1 to up to 5 ~y weight, respectively, then grinding the lllixlul~ to pass 70 Tyler mesh and pack~ging the result separately to form ~re~rding reagent) component 9.
Depending on the distance at which the slurry will have to be transported, a binding material required with a shorter setting time, typically between S and 50 minutes, can be made by mixing component 7 with component 8 in a ratio of (95 - 100):~0 - 5);on the other hand, with a longer setting time, typically between 40 and 120 minutes, the binding material can be made by mixing the component 7 with component 9 in aratio of (97 - 100):(0 - 3), when the slurry transportation distance is long.
A method for making the high pulp density, fast setting and high early strength 10 backflll slurry for underground backfill comprises: mixing one of, or a mixture of mine t~ilin~, natural sands, ground sands and industrial solid waste materials at any ratio with water to form sand slurry with a 63 - 82% of pulp density by weight in a station at the surface before it is transported to underground, then transported to a p1ace c10se to the back~lll stope through a pipe1ine by pumping or gravity; adding the lS binding material to the formed sand slurry in a pipeline through a feeding system, and mixing the binding material well with the sand slurry by turbulent flow inside the pipe; wherein the ~ tily of the binding material added is about 2 - 20% of the sand slurry by weight.
The ple~lion method for high pulp density, fast setting and high early strength backfill slurry for underground backfill comprises: mixing of mine tailings, natural sands, ground sands and industrial solid waste materials in any ratio, with component 7 ~as described above~ to form backfill material mixture; then adding water to the above ~ ure to make a slurry with 65 - 85% pulp density by weight, and S transporting the slurry to a place close to the bacl~'ill stope through the pipeline by pumping or gravity, wherein (accelerating reagent ~) component 8 ~described above) is added in an amount of 0 - 5% the weight of the formed slurry; wherein the backfill slurry is made uniform by the turbulent flow inside the pipe.
Another L~ ~dlion method for high pulp density bacfflll slurry comprises: adding 10 one of, or a ~ lure of natural sands, ground sands or industrial solid waste materials, in any ratio, to low pulp density tailings from mine processing mills to make a denser slurry with 62 - 80% pulp density sand sluny by weigl~; adding the binding material (described above) to the slurry through a feeding system with a quantity fiom 2 to 20% of the weight of the formed slurry to form a backfill slurry with 65 - 85% pulp 15 density.
DETAILED DESCRiPTION (}1~ THE INVENTION
Tailings from a gold mine is COI cen~ted from 20 - 30% solids to above 70% pulp density slurry. The present binding material is added through a measuring and mixing device to the formed tailing slu~y at a ratio of the binding material to the formed tailing slurry being 1 to 30. After mixing for 5 minutes, the slurry is sent to the underground mine through a pipeline. Samples modules (4" x 8n) with dirfel~n t S setting time are made for testing setting time and compressive strength. The result is shown as below:
The present binding m~tçri~l composition is as follows:
1. Sulph~ min~te cement clinkers 65%
2. Gypsum 20%
3. Hydroxide lime 5%
In order to increase the backfill body strength, the ratio of water to cement has to be S low on the one hand, but on other hand, to increase tlowability of the backfill slurry, much more water has to be used. The typical water to cement ratio is between 0.3 and 0.6 for Portland cement in order to get proper hydration, which is a relatively small ratio of water needed for hydration. But in order to meet the re~luirc,llc--~ for slurry transportation, pulp density of the slurry has to be less than 65 - 70%, to mal~e 10 it easily transportable to the mine stope through a pipeline. The excess amount of water in the backFIll slurry will have to be removed in the stope. Coarse aggregate~s such as s~nds, ground sands of coarse fractions from tailings are usually used in order to make dewatering easier. In addition to this problem, the cement backfill body takes 7 - 28 days to reach the required strength. As a result, a long waiting period is 15 necessary in order to continue mining the ores beside the backt~llled body. The cyc1e of drilling, blasting, ore transportation and backfill is prolonged.
There are other problems facing existing and tra lition~l Portland cement backflll methods:
1. A large amount of cement in the slurry is carried away by water during the 20 dewal~ling process. This not only causes ellv~n~ nt~l problems, but also decreases the strength of the backfill body.
2. Large spaces between the back~lll body and the roof of the stope cannot be fully filled due to slurry volume loss during dewdle~ g. Multip1e backfilling procedures are often require~ to fill up this space.
5 3. In order to create high permeability in the bacl~fiM body, only the coarse fractions of the tailings can be used as aggregate. Tailing utilizatioD effciency is therefore low, at less than 40~. The large quantity of unused fme tailings has to be disposed of on land at the surface, which causes e.lYilollnlelllal problems on mine surfaces.
10 4. The making of groun~ sands or purchase of sands to make up aggregates is costly, if the arnount of tailings available is not sufficient for backfilll.
5. Due to the long solîdifying period of the bacln~ill body of between 7 and 28 days, means delay before the next mining operation may begin, thus production efficiency is lowered.
15 In order to solve the technical problems listed a~ove, some mines have tried paste backfill. The binding material is still Portland cement, but the pulp density of the slurry has to be increased to more than 80%. Less water needs to be removed from this paste slurry in the mine stope. As a result, the strength of the backfil1 body increa~ses. However, due to the poor flow characteristics of the pa~ste, it raises a lot of transportation problems and it can only be used in large vertical height mines where gravity flow is used. Special mixing equipment such as 'double axis mixers' have to S be used for mixing and special positive displacement pumps for paste slurry transportation are required. The main problem~s associated with this method are: ~a) A pressure filter is required for making paste~ where capita1 cost is high and the process is complex, ~b~ Pipeline blockage occurs quite often due to too high pulp density, so that the paste slu~g transportation through a pipeline is very difflcult; (c) 10 Both curing periods and operation cycles of mining are too long, since Portland cement is used as the binding material; (d) Operating costs are high due to high cement consumption; (e3 It is difficult to fill up all of the space in a stope, because of the poor flow characteristics of the paste.
In order to solve the above problems, research on new binding materials and low pulp 15 density backfill methods have made progress in China. Chinese patents ZL90 103141.0 and ZL91 103829.9, to Henghu Sun et al., have disclosed a new process for metal mine backfill. These processes use so-called 'high water content' materials to replace Portland cement as binder to form a low pulp density slurry with 15 - 70%
pulp density. The "high water content" material binder is made of two equal parts 20 termed A and B materials. Both slurry A cont~ining the A binding material and s1urry B co~ -g the B binding material are sent to the mine stope through two separate CA 0223.7.726 1 998 - 04 - 22 pipe1ines. The two slurries are then mixed together at a place close to the mine stope for backfill. After 30 minutes7 the bacl~lll slurry solidifies in the stope without lusing any water.
However, there are some problems associated with this method: (i) The ratio between S A and B has to be exactly at one. Ch:lngin~ of this ratio may prevent the slurry from solidifying; (ii) The A and B slurries have to be transported through two separate pipelines. This directly increases the capital cost of the mining process; (iii) Since the two slurries have to be mixed at a place close to the backfill stope in the mine, s~ti~f~tory mixing requires that the pulp density of the slur~g must be less than 70%;
10 (iv) Due to the low solids content in the slurry, more hinder material is needed it high strength is required. This increases the cost of the hackflll.
United States Patent No. 5,141,365 issued August 25, 1992 to Smart discloses that a void in a mine is hackfilled by a backfill slurry comprising water, an inert filler, e.g.
mine tailings, and a binder, e.g. cement, lime or slag, to which a gelling agent, e.g.
15 sodium silicate, is added just before placement. The salient feature of this patent is that the bachSII slurry is made of tailings, water, Portland cement7 lime and slag.
United States Patent No. 4,101,333 issued July 18, 1978 to Wayment discloses a me~hod of ~ac~lling in underground mine operations by a mill tailings slurry which is dewatered to provide a material with a controller water content to permit the dewatered material to be used as a backfill witnout requiring any substantial dewatermg after placement and which material can, when desired, be mixed with selected quantities of cement to provide a mortar for ba~ llin~ or surt'ace covering.
The salient feature of this patent is using de-watered tailings for mine backfill The S dewatering of the backfi11 slurry underground in the mine is not necçss:lry. Port1and cement is mixed with prepared backfill aggregate to make a backfill slurry.
Both of tne aboYe two Unite~ States patents use Portland cement as binding material, and have the common disadvantage discussed above.
United States Patent No. 5,340,235 issued August 23, 1994 to Milliken discloses a 10 method for hydraulically b?,~filling empty mined salt cavities. The method comprises combining at least one pozzolanically active waste material with an effective amount of an ~lk~line earth metal in the form of an ~ lin~ earth metal hydroxide or jqlk~lin~
earth metal oxide and saturated brine to form a pozzolanic mixture, wherein the relative proportion,s of said po~zolanically active waste material, ~lk~ earth metal 15 hydroxide or ~lk~line earth metal oxide and sdluldled brine are sufficient for reaction under atmosphere conditions in said salt cavity to form a stable, low porosity, load bearing pozzolanic cement; and hydraulically depositing said pozzolanic ~ ure in the empty salt cavity United States Patent No. 5,464,473 is~sued November 7, 1995 to Shiao discloses a CA 0223.7.726 1998 - 04 - 22 backfill for an engineered barrier used to contain radinactive waste has a predel~ ined amount of clayic material and a predelel ~I~ined amount of a rein~olcement material with hydrophobic surface cl~lac~eristics. The reinforcement material may include hydrophobic compounds selected from group con~i~tin~ of S organic polymers or inorganic materials on which a 1ayer of hydrophobic compounds is formed. The hydrophobic reillforcement material results in the backfill ~ i"f~in;l~g a very low water permeability while providing high mechanical strength and other properties suitable for use in a repository of radioactive waste.
United States Patent No. 4,059,963 issued November 29, 1977 to Wayment discloses 10 a method of backfilling in underground mine operations by a mill tailings slurry which is dewatered to provide a material with a controlled water content to permit the dewatered m~t~ l to be used as a bacffill without requiring any subs~lial dewa~ g after placement and which material can, when desired, be mixed with selected quantities of cement to provide a mortar for ba~lrfilling or surface covering.
United States Patent No. 4,746,249 issued May 24, 1988 to Haigh et al. discloses an a4ueous slurry of backfill material e.g. slimes, includes a settable ttl~eri~l and an activator therefor, e.g. pulverized fuel ash and lime, and a lubricant e.g. clay and a plasticizer, e.g. a lignosulphonate so that the slurry can be pumped over long distances but will then set to develop high early strength.
United States Patent No. 5,106,422 issued April 21, 1992 to Bennett et al. discloses a rapid-setting self-hardening backfill composition and a method of in~t~ tion. The composition comprising a minor amount of Class C fly ash as a primary constituent and other filler m~teri~l~ such as Class F fly ash in major amount. When such 5 materia1s are combined with water in control1ed amount, they produce a backfilling material which is flowable and self-leveling for easy in~t~ tion in utility trenches and simi1ar excavations in street and roadway surfaces to support re1atively heavy co~ essive 10ads within relatively short periods of time without settling. The self-hardening ini~al1y flowable ~ ures attain considerable strength for withst~n-~in~
10 traffilc loads without undue settling in time periods of about 4 hours. The rapid-setting of the composition provides a rapidly ~t~in~l~le strength of the order of about 20 psi within about 4 hours to permit overlaying a wearing course of paving material and reopening of excavated areas of streets and roadways without undue traffic delays and congestion. The bac~fillin~ composition ranges in amount from about 2 to 10 parts 15 by weight filler material to about 1 part by weight Class C fly ash with suffilcient water to react with both Class C fly ash and filler material. The composition utilizes by-products of coal-fired power stations to form a most economic b~ llling material and method of utilization to provide both early strength and precisely controlled pe~lllanent strength to permit ready reexcavation.
20 Other patents disclosin~ new binder materials for mine backfill are: United States Patent No. 4,992,103, titled Cc.. ~ us Composition; United States Patent No.
CA 0223.7.726 1 998 - 04 - 22 4,798,628 titled Apparatus Delivering a Rapidly Setting Composition; and European Patent No. 286~9, titled Rapid set composition.
The major differences among the above patents are that different binders are used.
In some, binder consumption is very high at 300 - 500 kg per cubic metre. This is 5 only used for special cases in coal mines due to high cost.
SUMMARY OF THE INVENTJON
The present invention endeavours to solve the problems described above. Salient features of the method of the present invention are:
- Increase of tne backfill slurr,v pulp density to 65 - 85%.
10 - Use of all types of tailings, natural sands, ground sands and industrial solid waste materials as aggregates.
- Use of various proportions of basic binding materials, accelerating reagents, r~lardillg reagents, and suspension reagents to adjust the backfill slurry setting speed, ~setting time, early strength, flow characteristics and transportation.
15 - Alteration of binder addition procedures and slurry making procedures to obtain the required results.
- Large quantities of tailings and industrial solid wastes can be used for mine backfill.
- The making of high pulp density backfill slurry, such that underground de-watering is not required in some cases.
- Existing backfill technology can be used for various mine conditions through adjusting of the present method of making the present binding material composition, and the method of producing the new backfill slurry and its tran.~portation procedures.
10 Using the backfill technology of the present invention, full tailings from a mine mill can be used as aggregates. In prior methods, when using Portland cement as binder, the tailings must be classified to remove fine tailings; only about 40% of the tailings with particle si~s larger than 37 microns can be used as aggregates. In the present backfill technology, all tailings without classification can be used for backfill. R~Ckfill 15 slurry may be made by mixing any kind of tailings with water to make a slurry with 65 - ~5% pulp density by weight. It is then sent to the mine stope through one pipeline rather than two pipelines. The weight of the present binding material added to the backfill slurry is between 0.5 and 20% by weight. If there are no tailings available for bacffill, natural sands, ground sands, industrial solid waste materials or a mixture of thereof may be u~sed as aggregates. The natural sands include river sands, ~sea sands, sands from mwnlai~s. The ground sands are made from grinding rock into particle sizes of 0.04 - 5 mm. The industrial solid waste mq~ could be S iron smelter slag, power plant slag and various industrial waste slags.
According to the present invention, there is provided a high pulp density fast setting and high early strength backtill material and method for use in undergfoulld mines COII~hiSillg: one part of mine tailings, natural sands, ground sands, and solid industrial waste materials as aggre~ate; a binding material of between O.S and 20% by weight 10 mixed with water to form a slurry with 65 - 85% pulp density by weight; and transporting the slurry to the stope of a mine through a single pipeline.
Preferably, the present binding material is composed of six groups of components in the following ratios:
Component 1 can be one of, or a ~ e of sulpho-ah~ e cement clinkers, ferro-15 ~lumin~t~ cement clinkers, fluo~ e cement clinkers and high ~hlmin:~t~ cementclinkers, in any ratio. The concentration of component 1 in the binding material is between 40 - 90% by weight~ pl~rel~ly at 45 - 80% by weight and best at 50 - 70%
hy weight.
Component 2 can be one of, or a mixture of anhydrite and gypsum, in any ratio. The concentration of component 2 in the binding material is between 5 - 50% by weight, prerelably at 10 - 40% by weight and best at 15 - 40% by weight.
Component 3 can be one of, or a mixture of lime and hydroxide lime in any ratio.
5 The concentration of component 3 in the binding material is up to 30% by weight, preferably at 3 - 25% by weight and best at 5 - 20% by weight.
Component 4 can be one of, or a mixture of KCI, NaCI, CaC12, MgC12, ZnCI2, Na2C03t K2C03, Li2C0~, Li cc,..l~inii.g chemical compounds, Na2S04, K2S04, A12~S04)3, Na2S203, Na~, Na3P04, NaN03, K1~03, all alkalis, triethanolamine, 10 tri-isopropanolamine, c~balllide, in any ratio. The concentration of component 4 in the binding material is up to ~0 by weight, preferably at 0.05 - 6% by weight and best at 0.2 - 5% by weight. Component 4 is used as accelerating or/and high early strength reagent.
Component S can be one, or a llli~lule of sugars, molasses, lignosulphonates, tartaric 15 acid, tartrates salts, citric acid, citrate salts, boric acid and borate salt, in any ratio.
The concentration of component S in the binding material is up to 2% by weight, preferably at 0.05 - 1% by weight and best at 0.1 - 1% by weight. Comp~nent S is used as rel~ding or/and dispersion reagent.
Component 6 can be one of, or a ~ ur~ of bentl-nite, lime~stone, tlyash, silica fume, slag powder, cement, talc powder, clay powder, baux~te powder, anhydrite, gypsum, lime and hydroxide lime, in any ratio. The concentration of component 6 in the binding material is up to 31)% by weight, preferably at 0.1 - 10% by weight and best 5 at 0.5 - 5% by weight.
In another aspect of the present invention, there is provided a me~hod for producing a binding material for high pulp density, fast setting, high early strength b~
comprising: mixing of the above six groups of components in preselected ratios; an~
making and grinding the components to pass 100 Tyler mesh. P~ bly, the ratios 10 of the six components are:
(a) component 1: 45% - 80% by weight;
(b~ component 2: 10 - 40% by weight, (c~ component 3: 3 - 25% by weight;
~ d) component 4: 0.05 - 6% by weight, whereby component 4 is used as 15 accelerator or/and high early strength reagent;
(e~ component S: 0.1)5 - 1% by weight, wheleby component 5 is used as re~der or/and dispersion reagent; and ~f) component 6: 0.1 - 10% by weight.
In yet another aspect, the me~od of making high pulp density, fast setting and high early strength backfill slurry for underground backfill comprises using one of, or a 5 mixture of mine tailings, natural sands, ground sands and industrial solid waste materials at any ratio as backfill aggregate; mixing the backfill aggregate, water and material together uniformly to make a slurry with pulp density of 65 - 85 % by weight;
and transporting the slurry to the mine stope through a single pipeline by l~u114~illg or by gravity; wherein the ratio of the binding material to the backfil1 aggregate is between 1:5 and 1: 100 by weight.
A preferred method for prep~on of high pulp density7 fast setting and high early strength backfill slurry comprises the fol10wing steps: mixing one of, or a mixture of mine tailings7 natural sands, ground sands and industrial solid waste m~terial~7 in any ratio7 with water to form a homogenous and uniform sand slurry with a pulp 15 density of 63 - 82% by weight; adding binding material to the sand slurry through a feeder and mixing the slurry for 2 - 8 mim~tes in a ~ ur~ to form a backfill slurry with pulp density of 65 - 85% by weight; wherein the ratio of the newly invented binding material added to the backfill slurry is from 1:5 to 1:100 by weight7 and tran~sporting the bacloSII slurry to the stope in the mines through a pipeline by pumping or by gravity.
In another aspect, the ~ ~d~ion of high pulp density, fast setting and high early strength backfill slurry for underground backfi11 comprises the following steps: mixing one of, or a mixture of mine tailings, natural sands, ground sands or industrial solid S waste materials, in any rativ, with water to torm a homogenous and uniform sand slurry with a pulp density of 63 - 82% by weight; transporting the sand slurry to a site close to the stope in the mine through a pipeline by pumping or by gravity, at which site, adding binding material to the sand slurry inside the pipeline through a feeder, wherein the binding material added is well-mixed with the sand slurry through a 10 turbulent flow pattern inside the pipeline on its way to the stope; and wherein the formed backf111 slurry has a pulp density of 65 - 85 ~ by weight, and the ratio of the binding material added to the backfill slurry is from 1:5 to I:100 by weight.
Another method of providing binding material comprises: mixing components 1, 2 and 3 as defined above to form another component 7 as a binding material, wherein the 15 c(J-Ice~ alion by weight of each component in the binding material is as follows:
component 1 40 - 90%; component 2 5 - 50%; component 3 3 - 30%; grin~ling the component 7 to pass tOO Tyler mesh; mixing cvmponent 4 with component 6 in a ratio of 1 to up to 5 by weight, then grinding the l~ ure to pa~ss 70 Tyler mesh and packaging the result separately to form (accelerating reagent) component 8; mixing 2() component 5 with component 6 in a ratio of 1 to up to 5 ~y weight, respectively, then grinding the lllixlul~ to pass 70 Tyler mesh and pack~ging the result separately to form ~re~rding reagent) component 9.
Depending on the distance at which the slurry will have to be transported, a binding material required with a shorter setting time, typically between S and 50 minutes, can be made by mixing component 7 with component 8 in a ratio of (95 - 100):~0 - 5);on the other hand, with a longer setting time, typically between 40 and 120 minutes, the binding material can be made by mixing the component 7 with component 9 in aratio of (97 - 100):(0 - 3), when the slurry transportation distance is long.
A method for making the high pulp density, fast setting and high early strength 10 backflll slurry for underground backfill comprises: mixing one of, or a mixture of mine t~ilin~, natural sands, ground sands and industrial solid waste materials at any ratio with water to form sand slurry with a 63 - 82% of pulp density by weight in a station at the surface before it is transported to underground, then transported to a p1ace c10se to the back~lll stope through a pipe1ine by pumping or gravity; adding the lS binding material to the formed sand slurry in a pipeline through a feeding system, and mixing the binding material well with the sand slurry by turbulent flow inside the pipe; wherein the ~ tily of the binding material added is about 2 - 20% of the sand slurry by weight.
The ple~lion method for high pulp density, fast setting and high early strength backfill slurry for underground backfill comprises: mixing of mine tailings, natural sands, ground sands and industrial solid waste materials in any ratio, with component 7 ~as described above~ to form backfill material mixture; then adding water to the above ~ ure to make a slurry with 65 - 85% pulp density by weight, and S transporting the slurry to a place close to the bacl~'ill stope through the pipeline by pumping or gravity, wherein (accelerating reagent ~) component 8 ~described above) is added in an amount of 0 - 5% the weight of the formed slurry; wherein the backfill slurry is made uniform by the turbulent flow inside the pipe.
Another L~ ~dlion method for high pulp density bacfflll slurry comprises: adding 10 one of, or a ~ lure of natural sands, ground sands or industrial solid waste materials, in any ratio, to low pulp density tailings from mine processing mills to make a denser slurry with 62 - 80% pulp density sand sluny by weigl~; adding the binding material (described above) to the slurry through a feeding system with a quantity fiom 2 to 20% of the weight of the formed slurry to form a backfill slurry with 65 - 85% pulp 15 density.
DETAILED DESCRiPTION (}1~ THE INVENTION
Tailings from a gold mine is COI cen~ted from 20 - 30% solids to above 70% pulp density slurry. The present binding material is added through a measuring and mixing device to the formed tailing slu~y at a ratio of the binding material to the formed tailing slurry being 1 to 30. After mixing for 5 minutes, the slurry is sent to the underground mine through a pipeline. Samples modules (4" x 8n) with dirfel~n t S setting time are made for testing setting time and compressive strength. The result is shown as below:
The present binding m~tçri~l composition is as follows:
1. Sulph~ min~te cement clinkers 65%
2. Gypsum 20%
3. Hydroxide lime 5%
4. CaC12 3 %
5. Na2CO3 2%
6. LiOH 0.4%
7. Rf ntonite 4.6%
15 The initial setting time: 40 minutes The final setting time: 180 minutes Testing time: 8 hours I day 3 days 7 days Strength, psi: 19.6 52.3 67.8 87.4 EXAMPLE 2:
A slurry with 7~% pulp density by weight is made by mixing natural sands with water.
Mixture 1 is made of sulpho-alumim~te cement clinkers and ferro-alumin~te cement 5 clinkers at a ratio of 1:1 Mixture 2 is made of gypsum and anhydrite at a ratio of 2:8 Mixture 3 is made of hydroxide lime and lime at a ratio of 3:7 The binding material is composed of:
1. Mixture 1 65%
2. Mixture 2 20%
3 . Mixture 3 8%
4. K2C03 0.8%
5. NaCI 0 7%
6. 1,i2C03 0.2%
7. Molasses 0.3%
15 The initial setting time: 40 minutes The final setting time: 180 minutes Testing time: 8 hours I day 3 days 7 days Strength, psi: 19.6 52.3 67.8 87.4 EXAMPLE 2:
A slurry with 7~% pulp density by weight is made by mixing natural sands with water.
Mixture 1 is made of sulpho-alumim~te cement clinkers and ferro-alumin~te cement 5 clinkers at a ratio of 1:1 Mixture 2 is made of gypsum and anhydrite at a ratio of 2:8 Mixture 3 is made of hydroxide lime and lime at a ratio of 3:7 The binding material is composed of:
1. Mixture 1 65%
2. Mixture 2 20%
3 . Mixture 3 8%
4. K2C03 0.8%
5. NaCI 0 7%
6. 1,i2C03 0.2%
7. Molasses 0.3%
8. Flyash 5.0%
The above material is well mixed and ground to pass 100 Tyler mesh to make the binding material, which is then added to the above 75 % pulp density sand slurry with amount of 4% of the weight of the formed sand slurry. The mixture is tnen well mixed for S - 8 minutes and filled to exp~.rim~nt~l modules at 20 C. The result is S s} own ~elow:
The iI~itial setting time: 36 minutes The final setting time: 1~6 minut~s Testing time: 6 hours 1 day 3 days 7 days 28 days Strength, psi: 23.2 112.6 157.8 192.5 220.7 10 EXAMPLl~ 3:
Mix diy tailings with slag at a ratio of 1~ round the Illixlur~ to 0.04 - 5 mm.
Add water into the ~ ule to make a slurry of 72% solids. Mix sulpho-al~min~te cement clinkers and ferro~ min~te cement cli~ at ratio of 1:1 and grind the lui~lul~ to pass 100 Tyler mesh to produce component 1. The proportions for the 15 present binding l-ldlelial are:
1. Component 1 ~0%
2. Anhydrite 28 ~
3. Lime 8%
4. Limestone 4%
The materials listed above is ground to pass 100 Tyler mesh to ~orm the binding material. lt is then added to the formed sand slurry which is with 72% of pulp 5 density. The quantity added of the binding material is 5% of the weight of slurry.
After mixing for S - 8 ~llhl~lles, the slurry is filled to a few modules for strength testing. The result is as follows:
The initial setting time: 50 minll~s The final setting time: 200 minutes Testing time: 6 hours 1 day 3 days 7 days 28 days Strength, psi~ 18.8 87.8 138.3 167.1 lX8.9 EXAMPLE 4:
The binding material composed as shown in table 1, which is ground to pass totally 100 Tyler mesh, is separately mixed with classified tailing and alluvial sand slurries of 68%, 72% and 76% of pulp density. The ratios of the classified tailings alluvial sand to the binding material, Portland cement type 10, Poltland cement type 30, slag cement 10 - 90 are 15:1, 30:1, 45:1, respectively. The composition and strengths measured are shown in the following table 1:
EXAMPLE 5:
Mix dry tailing from the mine mill with ground sand at a ratio of the tailing to ground sand being 70:30. This formed ~ ure is then mixed with water to form sand s1urry S with pulp density of 70 wt. % . The binding material to be used, which is the same as in example 4, is added and mixed with the sand slurry to form backfill slurry. The backtill slurry is then transported through pipeline to a place where is about 30 - 50 meters from the backfill stope. The accelerating reagents such as sodium carbonate, lithium hydroxide and the suspension such as be-~ ile are added through measuring 10 devices. The quantities added of sodium carbonate, lithium hydroxide and b~nlollile are 3%, 0.02% and 5% of the weight of the bacffill slurry, respectively. These reagents are well mixed with the backfill slurry by a turbulent tlow inside the pipeline~
The slurry is then filled to the stope.
EXAMPLE 6:
15 Add sand, ground sand and ground industria1 solid waste material at an equal quantity, to tai1ing s1urry with pu1p density of 20 - 30% by weight from the mine mi11 to make sand slurry wi~ pulp density of 72% by weight. The binding materia1, same as in examp1e 1, is added to the formed sand s1uny. The weight of binder is 6% of the Table I
SUMMARY OF::~IYDRA~ B~AC~II;L STRENGTH, PSI
Classihed t~;lin~ a~ IIiiyiaI sand B d R~tio Pulp Deo~it~
m er S~d:b~d~
~e Cl-c~ifi~ Talngs a~uvials~d 68% 72% 72% 76%
~ ~r 69.7 151.0 89.3 146.7 The present 15-1 3~Y 93.7 178.7 108.1 185.1 binding material ~ 7 ~ 105 0 195 3 115 0 191 5 recipe 28~ 209.4 I I ~y 26.6 70.9 35.3 55.3 Sulph~ ~IIlmin ~ 30-1 3~y 38.7 94.2 50.6 86.0 cemen~ clinker 60%
2. 7~y 43.1 92.7 57.5 86.8 Anhy~i~e 28% 28~y 105.3 Lime 10% 1 ~y 151 42.6 25.0 29.7 45- 1 3 ~y 24.4 56.4 34.2 41.4 CaC03 2%
7~y 28.7 66.1 35.5 45.4 28~y 74.5 Portland Cement 15:1 Iday o o 6.1 12.5 Type 30 3 ~Y 1.5 2.2 14.8 29.6 7~y 6.1 8.3 29.8 42.3 28~y 20.1 24.3 37.3 66.2 Portland Cement 15:1 I day o o o 8.9 Type 10 3 ~Y 0 06 14.0 28.3 7~y 2.1 18.3 24.2 43.1 28~y 21.3 24.3 36.S 67.4 Slag Cement 15:1 ' d~y o o o o 10-90 Binder 3~y 12.4 11.5 0 0 7 ~y 28.5 26.3 7.6 9.4 28~y 60.0 67.0 24.7 28.5 weight of the formed sand slurry. After mixing for 5 - 8 minutes to form backfill slurry, the unirolll.ed backfill slurry is transported to the mine through a pipeline by pumping and filted in the stope The 3 days strength of tne sample i'rom the bacl~ïll body in the stope is above 80 psi.
S EXAMP~E 7:
This is a comparison between the binding mqteri~l and Portland cement type 10, type 3~ Firstly, natu~ sands are mixed with water to form various pulp density sand slurries of 68%, 70%, 72%, 74%, 76% and 78% respectively. Secondly, the present binding material, Portland cement type 10 and Portland cement type 30 are added into the formed sand slurries with various sand to binder ratios of 15:1, 20:1, 25:1, 30:1 and 35 :1, respectively, with a mixing time of 5 - 10 minUtes~ The formed slurries a re poured into 4" x 8" cylinder respectively. The strengths have been measured at a compressive testing, machine in 1 day, 3 days, 7 days and 28 days, which are listed in the following table 2.
15 Table 2 shows that the compressive strengths of using the present binding material are much higher than the compressive strengths of either using the Portland cement type 10 and type 30. Especially, very high early strengths have been achieved by using the present binding materia1. And 1 part of the binding material by weight used can replace 3 times of the Portland cement to get nearly the same compressive strength Table 2 SUM~IARY OF UNCONFlNED COM:PRESS~VE STRENGl'~
ALLUVIA.L SAND BACKF~LL
Binder Sand: binder 68% 70% 72% 74% 76~/. 78%
I d~y 51.2 79.1 111.4 151.0 131.8 143.9 The present 15-1 3d~y 65.0 99.8 125.0 178.7 143.9 179.9 binding material ~ 7d~y 75.3 105.8 145.1 195.3 178.9 192.0 recipe 28d~y 69.5 122.5 156.0 209.4 175.8 190.5 I d~y 25.5 39.9 54.9 70.9 66.8 74.5 Su~pho~ 20: 1 3 d~y 40.0 58.8 71.7 94.2 88.0 95.7 cemell~clinlcer S0% 7d y 49.4 58.5 79.8 92.7 93.7 105.0 A~hydrite30% 28d~y 55.4 67.7 84.5 105.3 114.7 113.4 3. I d~y 18.6 24.6 33.4 42.6 Lime IS%
4. 25: 1 3 d~y 28.2 34.2 47.7 56.4 5CaC03 2% 7~r 33.1 41.1 51.8 66.1 NuCO3 1% 28 d~y 37.1 42.1 60.0 74.5 6. I d-g 12.4 16.8 22.2 31.3 49.2 49.2 NaCI 1%
7 30:1 3d y 19.6 23.8 34.4 41.8 64.8 68.7 Sugar 0.2% 7 d-y 26.0 28.0 41.3 46.3 78.3 78.3 LiOH 0.0S% 28 d~y 29.7 33.4 43.0 51.0 84.0 85.6 Benl~ 0.7S% I d~y ~ . 36.2 34.9 35:1 3d~y . , . , 4~.4 48.7 7 d~y ~ 53.3 55.1 28 ~y ~ ~ ~ ~ 64.2 63.6 Portland Cement 15 1 It~y o o 6.1 , 12.5 17.8 Type 30 3d~y 13.5 11.4 14.8 ~ 29.6 40.8 7 d~y 20.3 17.6 29.6 ~ 42.3 69.4 28 d~y 24.7 24.8 37.3 ~ 66.2 95.0 Portland Cement 15:1 Id~y O I O O 0 8.9 11.5 Type 30 3d~y 8.8 lo.l 14.0 12.6 28.3 34.7 7d-y 16.1 13.8 24.2 18.3 43.1 54.
28d~y 20.5 25.1 36.5 36.9 67.4 68.
within 7 days.
Table 2 also shows very good properties of using the present binding m~t~ l, which can not be achieved with using Portland cement or any otner traditional binding material in the mining backfill ~leld.
The above material is well mixed and ground to pass 100 Tyler mesh to make the binding material, which is then added to the above 75 % pulp density sand slurry with amount of 4% of the weight of the formed sand slurry. The mixture is tnen well mixed for S - 8 minutes and filled to exp~.rim~nt~l modules at 20 C. The result is S s} own ~elow:
The iI~itial setting time: 36 minutes The final setting time: 1~6 minut~s Testing time: 6 hours 1 day 3 days 7 days 28 days Strength, psi: 23.2 112.6 157.8 192.5 220.7 10 EXAMPLl~ 3:
Mix diy tailings with slag at a ratio of 1~ round the Illixlur~ to 0.04 - 5 mm.
Add water into the ~ ule to make a slurry of 72% solids. Mix sulpho-al~min~te cement clinkers and ferro~ min~te cement cli~ at ratio of 1:1 and grind the lui~lul~ to pass 100 Tyler mesh to produce component 1. The proportions for the 15 present binding l-ldlelial are:
1. Component 1 ~0%
2. Anhydrite 28 ~
3. Lime 8%
4. Limestone 4%
The materials listed above is ground to pass 100 Tyler mesh to ~orm the binding material. lt is then added to the formed sand slurry which is with 72% of pulp 5 density. The quantity added of the binding material is 5% of the weight of slurry.
After mixing for S - 8 ~llhl~lles, the slurry is filled to a few modules for strength testing. The result is as follows:
The initial setting time: 50 minll~s The final setting time: 200 minutes Testing time: 6 hours 1 day 3 days 7 days 28 days Strength, psi~ 18.8 87.8 138.3 167.1 lX8.9 EXAMPLE 4:
The binding material composed as shown in table 1, which is ground to pass totally 100 Tyler mesh, is separately mixed with classified tailing and alluvial sand slurries of 68%, 72% and 76% of pulp density. The ratios of the classified tailings alluvial sand to the binding material, Portland cement type 10, Poltland cement type 30, slag cement 10 - 90 are 15:1, 30:1, 45:1, respectively. The composition and strengths measured are shown in the following table 1:
EXAMPLE 5:
Mix dry tailing from the mine mill with ground sand at a ratio of the tailing to ground sand being 70:30. This formed ~ ure is then mixed with water to form sand s1urry S with pulp density of 70 wt. % . The binding material to be used, which is the same as in example 4, is added and mixed with the sand slurry to form backfill slurry. The backtill slurry is then transported through pipeline to a place where is about 30 - 50 meters from the backfill stope. The accelerating reagents such as sodium carbonate, lithium hydroxide and the suspension such as be-~ ile are added through measuring 10 devices. The quantities added of sodium carbonate, lithium hydroxide and b~nlollile are 3%, 0.02% and 5% of the weight of the bacffill slurry, respectively. These reagents are well mixed with the backfill slurry by a turbulent tlow inside the pipeline~
The slurry is then filled to the stope.
EXAMPLE 6:
15 Add sand, ground sand and ground industria1 solid waste material at an equal quantity, to tai1ing s1urry with pu1p density of 20 - 30% by weight from the mine mi11 to make sand slurry wi~ pulp density of 72% by weight. The binding materia1, same as in examp1e 1, is added to the formed sand s1uny. The weight of binder is 6% of the Table I
SUMMARY OF::~IYDRA~ B~AC~II;L STRENGTH, PSI
Classihed t~;lin~ a~ IIiiyiaI sand B d R~tio Pulp Deo~it~
m er S~d:b~d~
~e Cl-c~ifi~ Talngs a~uvials~d 68% 72% 72% 76%
~ ~r 69.7 151.0 89.3 146.7 The present 15-1 3~Y 93.7 178.7 108.1 185.1 binding material ~ 7 ~ 105 0 195 3 115 0 191 5 recipe 28~ 209.4 I I ~y 26.6 70.9 35.3 55.3 Sulph~ ~IIlmin ~ 30-1 3~y 38.7 94.2 50.6 86.0 cemen~ clinker 60%
2. 7~y 43.1 92.7 57.5 86.8 Anhy~i~e 28% 28~y 105.3 Lime 10% 1 ~y 151 42.6 25.0 29.7 45- 1 3 ~y 24.4 56.4 34.2 41.4 CaC03 2%
7~y 28.7 66.1 35.5 45.4 28~y 74.5 Portland Cement 15:1 Iday o o 6.1 12.5 Type 30 3 ~Y 1.5 2.2 14.8 29.6 7~y 6.1 8.3 29.8 42.3 28~y 20.1 24.3 37.3 66.2 Portland Cement 15:1 I day o o o 8.9 Type 10 3 ~Y 0 06 14.0 28.3 7~y 2.1 18.3 24.2 43.1 28~y 21.3 24.3 36.S 67.4 Slag Cement 15:1 ' d~y o o o o 10-90 Binder 3~y 12.4 11.5 0 0 7 ~y 28.5 26.3 7.6 9.4 28~y 60.0 67.0 24.7 28.5 weight of the formed sand slurry. After mixing for 5 - 8 minutes to form backfill slurry, the unirolll.ed backfill slurry is transported to the mine through a pipeline by pumping and filted in the stope The 3 days strength of tne sample i'rom the bacl~ïll body in the stope is above 80 psi.
S EXAMP~E 7:
This is a comparison between the binding mqteri~l and Portland cement type 10, type 3~ Firstly, natu~ sands are mixed with water to form various pulp density sand slurries of 68%, 70%, 72%, 74%, 76% and 78% respectively. Secondly, the present binding material, Portland cement type 10 and Portland cement type 30 are added into the formed sand slurries with various sand to binder ratios of 15:1, 20:1, 25:1, 30:1 and 35 :1, respectively, with a mixing time of 5 - 10 minUtes~ The formed slurries a re poured into 4" x 8" cylinder respectively. The strengths have been measured at a compressive testing, machine in 1 day, 3 days, 7 days and 28 days, which are listed in the following table 2.
15 Table 2 shows that the compressive strengths of using the present binding material are much higher than the compressive strengths of either using the Portland cement type 10 and type 30. Especially, very high early strengths have been achieved by using the present binding materia1. And 1 part of the binding material by weight used can replace 3 times of the Portland cement to get nearly the same compressive strength Table 2 SUM~IARY OF UNCONFlNED COM:PRESS~VE STRENGl'~
ALLUVIA.L SAND BACKF~LL
Binder Sand: binder 68% 70% 72% 74% 76~/. 78%
I d~y 51.2 79.1 111.4 151.0 131.8 143.9 The present 15-1 3d~y 65.0 99.8 125.0 178.7 143.9 179.9 binding material ~ 7d~y 75.3 105.8 145.1 195.3 178.9 192.0 recipe 28d~y 69.5 122.5 156.0 209.4 175.8 190.5 I d~y 25.5 39.9 54.9 70.9 66.8 74.5 Su~pho~ 20: 1 3 d~y 40.0 58.8 71.7 94.2 88.0 95.7 cemell~clinlcer S0% 7d y 49.4 58.5 79.8 92.7 93.7 105.0 A~hydrite30% 28d~y 55.4 67.7 84.5 105.3 114.7 113.4 3. I d~y 18.6 24.6 33.4 42.6 Lime IS%
4. 25: 1 3 d~y 28.2 34.2 47.7 56.4 5CaC03 2% 7~r 33.1 41.1 51.8 66.1 NuCO3 1% 28 d~y 37.1 42.1 60.0 74.5 6. I d-g 12.4 16.8 22.2 31.3 49.2 49.2 NaCI 1%
7 30:1 3d y 19.6 23.8 34.4 41.8 64.8 68.7 Sugar 0.2% 7 d-y 26.0 28.0 41.3 46.3 78.3 78.3 LiOH 0.0S% 28 d~y 29.7 33.4 43.0 51.0 84.0 85.6 Benl~ 0.7S% I d~y ~ . 36.2 34.9 35:1 3d~y . , . , 4~.4 48.7 7 d~y ~ 53.3 55.1 28 ~y ~ ~ ~ ~ 64.2 63.6 Portland Cement 15 1 It~y o o 6.1 , 12.5 17.8 Type 30 3d~y 13.5 11.4 14.8 ~ 29.6 40.8 7 d~y 20.3 17.6 29.6 ~ 42.3 69.4 28 d~y 24.7 24.8 37.3 ~ 66.2 95.0 Portland Cement 15:1 Id~y O I O O 0 8.9 11.5 Type 30 3d~y 8.8 lo.l 14.0 12.6 28.3 34.7 7d-y 16.1 13.8 24.2 18.3 43.1 54.
28d~y 20.5 25.1 36.5 36.9 67.4 68.
within 7 days.
Table 2 also shows very good properties of using the present binding m~t~ l, which can not be achieved with using Portland cement or any otner traditional binding material in the mining backfill ~leld.
Claims (10)
1 CLAIMS:
1. A binding material for use in mine-backfill, comprising at least three of six components; said six components being: component 1: one of, or a mixture of sulpho-aluminate cement clinkers, ferro-aluminate cement clinkers, fluo-aluminate cement clinkers and high aluminate cement clinkers, in any ratio; wherein the concentration of component 1 in the binding material is between 40 - 90% by weight;
component 2: one of, or a mixture of anhydrite and gypsum, in any ratio;
wherein the concentration of component 2 in the binding material is between 5 - 50% by weight;
component 3: one of, or a mixture of lime and hydroxide lime in any ratio;
wherein the concentration of component 3 in the binding material is up to 30% by weight;
component 4: one of, or a mixture of KCl, NaCl, CaCl2, MgCl2, ZnCl2, Na2CO3, K2CO3, Li2CO3, Li containing chemical compounds, Na2SO4, K2SO4, Al2(SO4)3, Na2S2O3, NaF, Na3PO4, NaNO3, KNO3, all alkalis, triethanolamine, tri-isopropanolamine, carbamide, in any ratio; wherein the concentration of component 4 in the binding material is up to 8% by weight;
component 5: one, or a mixture of sugars, molasses, lignosulphonates, tartaric acid, tartrates salts, citric acid, citrate salts, boric acid and borate salt, in any ratio; wherein
1. A binding material for use in mine-backfill, comprising at least three of six components; said six components being: component 1: one of, or a mixture of sulpho-aluminate cement clinkers, ferro-aluminate cement clinkers, fluo-aluminate cement clinkers and high aluminate cement clinkers, in any ratio; wherein the concentration of component 1 in the binding material is between 40 - 90% by weight;
component 2: one of, or a mixture of anhydrite and gypsum, in any ratio;
wherein the concentration of component 2 in the binding material is between 5 - 50% by weight;
component 3: one of, or a mixture of lime and hydroxide lime in any ratio;
wherein the concentration of component 3 in the binding material is up to 30% by weight;
component 4: one of, or a mixture of KCl, NaCl, CaCl2, MgCl2, ZnCl2, Na2CO3, K2CO3, Li2CO3, Li containing chemical compounds, Na2SO4, K2SO4, Al2(SO4)3, Na2S2O3, NaF, Na3PO4, NaNO3, KNO3, all alkalis, triethanolamine, tri-isopropanolamine, carbamide, in any ratio; wherein the concentration of component 4 in the binding material is up to 8% by weight;
component 5: one, or a mixture of sugars, molasses, lignosulphonates, tartaric acid, tartrates salts, citric acid, citrate salts, boric acid and borate salt, in any ratio; wherein
2 the concentration of component 5 in the binding material is up to 2% by weight; and component 6: one of, or a mixture of bentonite, limestone, flyash, silica fume, slag powder, cement, talc powder, clay powder, bauxite powder, anhydrite, gypsum, lime and hydroxide lime, in any ratio; wherein the concentration of component 6 in the binding material is up to 30% by weight.
2. The binding material as defined in claim 1, wherein the components are mixed in preselected ratios and ground and the components having to pass 100 Tyler mesh;
the ratios:
component 1: 45% - 80% by weight;
component 2: 10 - 40% by weight;
component 3: 3 - 25% by weight;
component 4: 0.05 - 6% by weight;
component 5: 0.05 - 1% by weight; and component 6: 0.1 - 10% by weight.
2. The binding material as defined in claim 1, wherein the components are mixed in preselected ratios and ground and the components having to pass 100 Tyler mesh;
the ratios:
component 1: 45% - 80% by weight;
component 2: 10 - 40% by weight;
component 3: 3 - 25% by weight;
component 4: 0.05 - 6% by weight;
component 5: 0.05 - 1% by weight; and component 6: 0.1 - 10% by weight.
3. A method for providing a high pulp density fast setting and high early strength backfill for use in underground mines, utilizing a binding material as defined in claims 1 or 2, comprising: preparing one part of mine tailings, natural sands, ground sands, or solid industrial waste materials as aggregate; adding the binding material of between 0.5 and 20% by weight of the aggregate mixed with water to form a slurry with 65-85% pulp density by weight; and transporting the slurry to the slope of a mine through a single pipeline.
4. A method of making high pulp density, fast setting and high early strength backfill slurry for underground backfill, utilizing a binding material as defined in claims 1 or 2, comprising: using one of, or a mixture of mine tailings, natural sands, ground sands and industrial solid waste materials at any ratio as backfill aggregate;
mixing the backfill aggregate, water and the binding material together uniformly to make a slurry with pulp density of 65-85% by weight; and transporting the slurry to the mine stope through a single pipeline by pumping or by gravity; wherein the ratio of the binding material to the backfill aggregate is between 1:5 and 1:100 by weight.
mixing the backfill aggregate, water and the binding material together uniformly to make a slurry with pulp density of 65-85% by weight; and transporting the slurry to the mine stope through a single pipeline by pumping or by gravity; wherein the ratio of the binding material to the backfill aggregate is between 1:5 and 1:100 by weight.
5. A method for preparation of high pulp density, fast setting and high early strength backfill slurry, utilizing a binding material as defined in claims 1 or 2, comprising the following steps: mixing one of, or a mixture of mine tailings, natural sands, ground sands and industrial solid waste materials, in any ratio, with water to form a homogenous and uniform sand slurry with a pulp density of 63-82% by weight; adding the binding material to the sand slurry through a feeder and mixing the slurry for 2-8 minutes in a mixture to form a backfill slurry with pulp density of 65-85% by weight; wherein the ratio of the newly invented binding material added to the backfill slurry is from 1:5 to 1:100 by weight; and transporting the backfill slurry to the slope in the mines through a pipeline by pumping or by gravity.
6. A method for the preparation of high pulp density, fast setting and high early strength backfill slurry for underground backfill, utilizing a binding material as defined in claims 2 or 3, comprising the following steps: mixing one of, or a mixture of mine tailings, natural sands, ground sands or industrial solid waste materials, in any ratio, with water to form a homogenous and uniform sand slurry with a pulp density of 63-82% by weight; transporting the sand slurry to a site close to the slope in the mine through a pipeline by pumping or by gravity, at which site, adding the binding material to the sand slurry inside the pipeline through a feeder, wherein the binding material added is well-mixed with the sand slurry through a turbulent flow pattern inside the pipeline on its way to the slope; and wherein the formed backfill slurry has a pulp density of 65-85% by weight, and the ratio of the binding material added to the backfill slurry is from 1:5 to 1:100 by weight.
7. A method of providing binding material, comprising: mining components 1, 2 and 3 as defined in claim 1 to form another component 7 as a binding material, wherein the concentration by weight of each component in the binding material is as follows: component 1 40-90%; component 25-50%; component 3 3-30%;
grinding the component 7 to pass 100 Tyler mesh; mixing component 4 with component 6 in a ratio of 1 to up to 5 by weight, then grinding the mixture to pass 70 Tyler mesh and packaging the result separately to form (accelerating reagent) component 8; mixing component 5 with component 6 in a ratio of 1 to up to 5 by weight, respectively, then grinding the mixture to pass 70 Tyler mesh and packaging the result separately to form (retarding reagent) component 9.
grinding the component 7 to pass 100 Tyler mesh; mixing component 4 with component 6 in a ratio of 1 to up to 5 by weight, then grinding the mixture to pass 70 Tyler mesh and packaging the result separately to form (accelerating reagent) component 8; mixing component 5 with component 6 in a ratio of 1 to up to 5 by weight, respectively, then grinding the mixture to pass 70 Tyler mesh and packaging the result separately to form (retarding reagent) component 9.
8. A method for making the high pulp density, fast setting and high early strength backfill slurry for underground backfill, utilizing a binding material as defined in claims 1, 2 or 7, comprising: mixing one of, or a mixture of mine tailings, natural sands, ground sands and industrial solid waste materials at any ratio with water to form sand slurry with a 63-82% of pulp density by weight in a station at the surface before it is transported to underground, then transported to a place close to the backfill slope through a pipeline by pumping or gravity; adding the binding material to the formed sand slurry in a pipeline through a feeding system, and mixing the binding material well with the sand slurry by turbulent flow inside the pipe; wherein the quantity of the binding material added is about 2-20% of the sand slurry by weight.
9. A method for making high pulp density, fast setting and high early strength backfill slurry for underground backfill comprises: mixing of mine tailings, natural sands, ground sands and industrial solid waste materials in any ratio, with component 7 as defined in claim 7 to form backfill material mixture; then adding water to the above mixture to make a slurry with 65-85% pulp density by weight; and transporting the slurry to a place close to the backfill slope through the pipeline by pumping or gravity, wherein component 8 as defined in claim 7 is added in an amount of 0-5% the weight of the formed slurry; wherein the backfill slurry is made uniform by the turbulent flow inside the pipe.
10. A method for preparing high pulp density backfill slurry, utilizing a binding material as defined in claims 1, 2 or 7, comprising: adding one of, or a mixture of natural sands, ground sands or industrial solid waste materials, in any ratio, to low pulp density tailings from mine processing mills to make a denser slurry with 62-80% pulp density sand slurry by weight; adding the binding material to the slurry through a feeding system with a quantity from 2 to 20% of the weight of the formed slurry to form a backfill slurry with 65-85% pulp density.
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|---|---|---|---|
| CA 2235526 CA2235526C (en) | 1997-04-24 | 1998-04-22 | High pulp density fast setting and high early strength backfill method and material |
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| CA2,203,575 | 1997-04-24 | ||
| CA2203575 | 1997-04-24 | ||
| CA 2235526 CA2235526C (en) | 1997-04-24 | 1998-04-22 | High pulp density fast setting and high early strength backfill method and material |
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| CA2235526C true CA2235526C (en) | 1999-10-05 |
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| US6428107B1 (en) | 2000-11-28 | 2002-08-06 | Inco Limited | Heat added to underground cemented fill to obtain both early and long term strength increases |
| US11095101B2 (en) | 2016-09-06 | 2021-08-17 | Quanta Associates, L.P. | Repurposing pipeline for electrical cable |
| CN111537418B (en) * | 2020-04-27 | 2022-09-23 | 哈尔滨工业大学 | Method for evaluating grouting performance of cement asphalt composite concrete cementing material |
| CN112593528B (en) * | 2020-12-25 | 2022-05-17 | 洛阳理工学院 | Molybdenum ore tailing sand reinforcing and anti-leakage method and building structure thereof |
| CN114057415A (en) * | 2021-12-08 | 2022-02-18 | 西安建筑科技大学 | Multi-solid waste gel material, multi-solid waste filling material based on gel material, and preparation method and application of multi-solid waste filling material |
| CN116813276B (en) * | 2023-06-30 | 2024-04-12 | 金徽矿业股份有限公司 | Method for efficiently preparing fast-strength tailing filling paste material |
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