CN115093152A - Composite chromium-reducing grinding aid and preparation method thereof - Google Patents
Composite chromium-reducing grinding aid and preparation method thereof Download PDFInfo
- Publication number
- CN115093152A CN115093152A CN202210662687.XA CN202210662687A CN115093152A CN 115093152 A CN115093152 A CN 115093152A CN 202210662687 A CN202210662687 A CN 202210662687A CN 115093152 A CN115093152 A CN 115093152A
- Authority
- CN
- China
- Prior art keywords
- chromium
- reducing
- grinding aid
- component
- stirring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
- C04B40/0028—Aspects relating to the mixing step of the mortar preparation
- C04B40/0039—Premixtures of ingredients
-
- 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
- C04B7/00—Hydraulic cements
- C04B7/36—Manufacture of hydraulic cements in general
- C04B7/48—Clinker treatment
- C04B7/52—Grinding ; After-treatment of ground cement
-
- 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
- C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
- C04B2103/52—Grinding aids; Additives added during grinding
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
Abstract
The invention discloses a composite chromium-reducing grinding aid and a preparation method thereof, relating to the field of building materials, wherein the raw materials comprise 15-30 wt% of chromium-reducing component, 5-10 wt% of antioxidant component, 20-40 wt% of grinding-aid component and the balance of water; the chromium reducing component is thiourea dioxide and/or sodium cyanoborohydride; the preparation method comprises the steps of adding the grinding-aid components and water at normal temperature, and uniformly stirring; then adding the antioxidant component and stirring uniformly; and (4) keeping the stirring state, adding the chromium reduction component, and continuously stirring uniformly to obtain a finished product of the composite chromium reduction grinding aid. The composite chromium-reducing grinding aid provided by the invention has a good chromium-reducing effect, does not rebound, has the characteristics of high temperature resistance, oxidation resistance and the like, and can be well adapted to the change of the working condition temperature of cement; the production cost is lower, the mixing amount is lower than that of the common chromium reducing agent, and the chromium reducing agent has the advantages of improving the yield, reducing the consumption, improving the performance of cement and reducing the production cost.
Description
Technical Field
The invention relates to the field of building materials, in particular to a chromium-reducing grinding aid and a preparation method thereof.
Background
Hexavalent chromium has dangerous characteristics of strong oxidizability, corrosivity and the like, and can cause 'skin eczema' after being contacted for a long time, and even can cause cancer, mutation and other adverse consequences after being taken in a large amount; under the environment of long-term rain water showering, underground water quality and soil chromium pollution can be caused, and the hidden danger of chromium poisoning is generated. In order to control the content of water-soluble hexavalent chromium in cement, the state issues a mandatory standard GB 31893-2015 limit and determination method for water-soluble chromium (VI) in cement, and the standard clearly specifies that the content of water-soluble chromium (VI) in cement is not more than 10 mg/kg.
The method for controlling water-soluble chromium (VI) in cement is an effective method which adopts two modes of head control and tail control in the main method at present, and reduces hexavalent chromium with high toxicity into trivalent chromium with low toxicity by adopting a chromium reducing agent under the condition that the raw materials of the cement cannot be changed. However, existing chromium reducer products suffer from various drawbacks and problems: the powder chromium reducing agent generally adopts ferrous sulfate and Sn 2+ Salt, etc. For example, in the prior art, chinese patent application CN113480219A provides a chromium-reducing agent for reducing water-soluble chromium (vi) in cement, which comprises chromium reducing agents (sodium thiosulfate, ferrous sulfate, ferrous citrate, nitrilotriacetic acid, anhydrous sodium sulfite), stabilizers (ascorbic acid VC, nitrilotriacetic acid, oligomeric glucose, polydextrose, sodium oxalate, disodium edetate), catalysts (anhydrous sodium sulfate, calcium formate) and dispersing carriers (fly ash, heavy calcium carbonate powder). For example, the raw materials of the compound reducing agent for hexavalent chromium in cement provided by the patent CN106365479B granted in china include sodium sulfite, ferrous sulfate, manganese sulfate and stannous sulfate. Some of the chromium reducing agents have the defects of high possibility of being oxidized, easy caking, inaccurate metering and poor high-temperature resistance, and some chromium reducing agents have the defects of high purchase cost, uneven dispersion, low cost performance, influence on the performance of cement and the like, so that the chromium reducing effect is not ideal and cannot be applied to production practice.
Chinese patent application CN111198184A discloses a method for detecting hexavalent chromium ions in soil, which comprises adding a digesting agent (sodium hydroxide and sodium carbonate), sodium borohydride and a phosphate buffer solution into the soil, heating and stirring; after cooling, EDTA disodium salt is added, heating and stirring are continued, after supernatant liquid is obtained through centrifugation, concentrated nitric acid is added, volume is fixed, and finally hexavalent chromium of the solution to be detected is detected by a diphenylcarbonyl dihydrazide spectrophotometry.
Too much addition of these various types of cement chromium reducing agents can also have an adverse effect on the cement performance; the liquid chromium reducing agent has ideal chromium reducing effect, but has high price, the cost of reducing 1ppm hexavalent chromium by using the liquid chromium reducing agent exceeds 1.5 yuan/ton, and only has single chromium reducing effect.
The existing cement grinding aids only have grinding and enhancing effects, and have no effect of reducing chromium. Therefore, when cement enterprises grind cement, the chromium reducing agent is added additionally while adding the common grinding aid, which causes additional increase of production cost.
In the prior art, for example, a composite cement chromium-removing grinding aid provided by chinese patent application CN109761518A, raw materials include Cr reducing component (ferrous sulfate or stannous chloride), triethanolamine, glycerol, isooctyl alcohol phosphate, antioxidant (tannic acid), surfactant, reduction enhancer; the reduction reinforcing agent is black particles obtained by extracting dry pine bark powder with hot water to obtain an extracting solution, weighing ferrous sulfate and ferric chloride, mixing the ferrous sulfate and the ferric chloride to prepare Fe ion liquid, mixing and stirring the Fe ion liquid with the pine bark extracting solution for reaction, performing suction filtration, adding 3-mercaptopropionic acid into the obtained black solid, adjusting the pH value to be 8, performing ultrasonic treatment, suction filtration, washing with ethanol, suction filtration and drying, and the black nanoparticles have high adsorption performance. Hexavalent chromium is reduced to trivalent chromium and is adsorbed on the surface of the black nano-particles in the form of iron-chromium oxide; free and unadsorbed hexavalent chromium can continuously generate oxidation-reduction reaction with Cr reducing components in the grinding aid, so that the hexavalent chromium is efficiently reduced. However, tannin and other components in the chromium-removing grinding aid can also cause cement retardation, and the preparation process is too complex, long in time consumption, high in cost and difficult to implement and apply.
In conclusion, if the grinding aid with high cost performance, good chromium reduction effect, prevention of trivalent chromium from being oxidized again and no adverse effect on the coagulation rate of cement is prepared, the cost can be greatly saved and the efficiency can be improved.
Disclosure of Invention
In view of the above deficiencies of the prior art, the present invention provides, and is specifically embodied by, the following techniques.
The composite chromium-reducing grinding aid is characterized in that raw materials comprise 15-30 wt% of chromium-reducing component, 5-10 wt% of antioxidant component, 20-40 wt% of grinding aid component and the balance of water; the chromium reducing component is thiourea dioxide and/or sodium cyanoborohydride.
Preferably, the raw materials of the composite chromium-reducing grinding aid comprise 25 wt% of chromium-reducing component, 8 wt% of antioxidant component, 30 wt% of grinding aid component and the balance of water.
The composite chromium-reducing grinding aid provided by the invention can be stored for a long time, has an obvious and long-term stable chromium-reducing effect, and has grinding-assisting and reinforcing effects; solves the problems of single function, high use cost, poor chromium reduction effect, easy oxidation rebound and the like of the existing chromium reduction agent. The invention uses thiourea dioxide and/or sodium cyanoborohydride as the chromium-reducing component, compared with the prior common chromium-reducing agents such as thiosulfate, ferrite, sulfite, stannous salt, sodium borohydride and the like, the thiourea dioxide has strong reducibility, good stability and safety performance, does not belong to carcinogenic or dangerous chemicals, and has no pollution during production and use. The sodium cyanoborohydride also has strong reducibility, and compared with sodium borohydride, although the reduction effect is slightly poor, the sodium borohydride is violently reacted and belongs to an explosive product, so that the use of the sodium cyanoborohydride has a large safety risk, and the sodium cyanoborohydride is mild and has better safety performance. Thiourea dioxide is stable under an acidic condition, reacts in an alkaline solution to generate sulfinic acid with strong reducibility, and sodium cyanoborohydride is dissolved in water to be acidic. The hexavalent chromium is dissolved in the alkaline water solution after the cement meets water, and the chromium reducing component can quickly reduce the hexavalent chromium into trivalent chromium. Therefore, thiourea dioxide and sodium cyanoborohydride are used as chromium reduction components in a matched mode, compared with the mode that sodium cyanoborohydride or sodium borohydride is used alone, the chromium reduction grinding aid is higher in overall stability, the chromium reduction effect on cement is better, and reduced trivalent chromium cannot be oxidized into hexavalent chromium again.
More preferably, the mass ratio of thiourea dioxide to sodium cyanoborohydride is 3 (1-2).
Further preferably, the mass ratio of thiourea dioxide to sodium cyanoborohydride is 2: 1.
Preferably, the antioxidant component is one or more of formamide, methacrylic acid and sulfosalicylic acid. The antioxidant formamide, methacrylic acid and sulfosalicylic acid used in the invention can promote the conversion of hexavalent chromium into trivalent chromium, and also has the effect of stabilizing the trivalent chromium, so that the trivalent chromium is prevented from being oxidized into hexavalent chromium again in a high-temperature oxidation environment; compared with conventional raw materials for the chromium reducing agent, such as ascorbic acid, nitrilotriacetic acid, oligo-glucose, polydextrose, sodium oxalate, ethylene diamine tetraacetic acid and the like, formamide, methacrylic acid and sulfosalicylic acid have oxidation resistance and have no adverse effect on the performance of cement, and can promote hexavalent chromium to be reduced into trivalent chromium by reaction and inhibit the trivalent chromium from being oxidized into hexavalent chromium.
Preferably, the grinding aid component consists of alcohol amine and modified lignosulfonate, wherein the modified lignosulfonate accounts for 2-10% of the total mass of the composite chromium-reducing grinding aid; the preparation method of the modified lignosulfonate comprises the following steps:
p1, dissolving 50-60 parts by weight of lignosulfonate in water, heating to 75-85 ℃, adjusting the pH value of the solution to 9-10, and stirring for 20-35 min;
p2, adding dilute nitric acid into the mixed solution obtained in the step P1 to adjust the pH value of the solution to 8-9, and then adding 5-10 parts by weight of H 2 O 2 Or KMnO 4 And 1-2 parts by weight of FeO or CuO, reacting for 0.5-1 h;
p3, adding 40-50% by mass of formaldehyde aqueous solution and fatty amine into the mixed solution obtained in the step P2, wherein the total parts of the formaldehyde aqueous solution and the fatty amine are 20-30 parts by weight, the ratio of the mass of the formaldehyde to the mass of the fatty amine is 1:1, and reacting for 1-1.5 h;
p4, adding 3-5 parts by weight of formaldehyde aqueous solution with the mass fraction of 40-50% for reaction for 0.5-1h, finally adding 3-6 parts by weight of sodium carboxymethylcellulose and 2-4 parts by weight of sodium sulfate, stirring for 10-30min, and cooling to obtain the modified lignosulfonate.
The alcohol amine plays roles in grinding aid, enhancing and improving cement performance, can improve the output per machine hour of cement, and reduces the power consumption of grinding. The modified lignosulfonate prepared by the modification method has the advantages of improving air-entraining performance, obviously weakening retardation, increasing the strength of cement, reducing the water demand of the cement and improving the comprehensive performance of the cement.
More preferably, the alcohol amine is one or more of triethanolamine, triisopropanolamine, tripropylene glycol, diethanol monoisopropanolamine and monoethanol diisopropanolamine.
The invention also provides a preparation method of the composite chromium-reducing grinding aid, which comprises the following steps:
s1, adding the grinding aid component and water at normal temperature, and stirring uniformly;
s2, adding the antioxidant component and stirring uniformly; and keeping stirring, adding the chromium-reducing component, and continuously stirring uniformly to obtain a finished product of the composite chromium-reducing grinding aid.
Preferably, in the preparation method of the composite chromium-reducing grinding aid, the stirring rotation speeds of the steps S1 and S2 are both 60-150 rpm; the stirring time in the step S1 is 3-6min, the stirring time after the antioxidant component is added in the step S2 is 5-10min, and the stirring time after the chromium-reducing component is added is 15-30 min.
The composite chromium-reducing grinding aid provided by the invention can adjust the proportion of the reducing component and the antioxidant component according to the content of water-soluble chromium (VI) in cement and the required chromium-reducing amplitude, and the mixing amount of the composite chromium-reducing grinding aid is generally 0.03-0.1% of the mass of the cement and can be adjusted.
Generally speaking, the chromium-reducing grinding aid is conveyed to a cement grinding workshop, stored in an existing grinding aid storage tank, accurately and stably metered by controlling the mixing amount through a flow pump, added into a grinding material, ground through a grinding machine, fully mixed with a cement finished product, and conveyed to a cement warehouse for homogenization and storage. The composite chromium-reducing grinding aid can be widely applied to producing low-chromium high-performance cement products.
Compared with the prior art, the invention has the advantages that:
1. the composite chromium-reducing grinding aid provided by the invention has the advantages that the adopted raw materials are good in compatibility and are dissolved in water, the components of the finished product are uniform, no precipitate is generated, and the metering is convenient and accurate; the chromium-reducing agent has the characteristics of long storage time in a closed container, good chromium-reducing effect, no rebound, high temperature resistance, oxidation resistance and the like, and can be well adapted to the change of the working condition temperature of cement;
2. the production cost is lower, the mixing amount is lower than that of the common chromium reducing agent, and the chromium reducing agent has the advantages of improving the yield, reducing the consumption, improving the cement performance and reducing the production cost;
3. the preparation method is simple, the formula can be flexibly adjusted according to the requirement of the chromium reduction effect, and the operation and the quality control are easy; the cement grinding aid storage and addition device is convenient to use, can directly utilize the existing cement grinding aid storage and addition equipment for cement enterprises, does not need to increase the investment additionally, and has obvious technical advantages and wide market prospect.
Detailed Description
The technical solutions of the present invention will be described clearly and completely below, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The raw materials of the composite chromium-reducing grinding aid provided by the embodiment comprise 25 wt% of chromium-reducing component (thiourea dioxide), 8 wt% of antioxidant component (methacrylic acid), 30 wt% of grinding aid component (triethanolamine 20 wt%, diethanol monoisopropanolamine 7 wt%, modified calcium lignosulfonate 3 wt%), and the balance of water.
The preparation method of the composite chromium-reducing grinding aid provided by the embodiment comprises the following steps:
s1, adding a chromium reduction component (thiourea dioxide) and water at normal temperature, and stirring at 100rpm for 5 min;
s2, adding an antioxidant component (methacrylic acid), and stirring at 100rpm for 8 min; and (3) keeping the stirring state, adding grinding aid components (triethanolamine and diethanol monoisopropanolamine), then adding the grinding aid components (modified calcium lignosulfonate), and continuously stirring at 100rpm for 20min to obtain the finished product of the composite chromium-reducing grinding aid.
The preparation method of the modified calcium lignosulphonate comprises the following steps:
p1, dissolving 55 parts of lignosulfonate (calcium lignosulfonate) in water, heating to 80 ℃, adjusting the pH value of the solution to 9-10, and stirring for 30 min;
p2, adding dilute nitric acid (1mol/L) into the mixed solution obtained in the step P1 to adjust the pH value of the solution to 8-9, and then adding 8 parts of H 2 O 2 And 2 parts of FeO, reacting for 1 hour;
p3, adding a formaldehyde aqueous solution (mass fraction of 50%) and fatty amine (dodecylamine) into the mixed solution obtained in the step P2, wherein the total parts of the formaldehyde aqueous solution and the fatty amine are 30 parts, the mass ratio of the formaldehyde to the fatty amine is 1:1, and reacting for 1.5 h;
and P4, adding 5 parts by mass of formaldehyde aqueous solution (mass fraction is 50%) for reaction for 1h, finally adding 5 parts by mass of sodium carboxymethylcellulose and 3 parts by mass of sodium sulfate, stirring for 25min, and cooling to obtain the modified calcium lignosulfonate.
Example 2
The raw materials of the composite chromium-reducing grinding aid provided by the embodiment comprise 15 wt% of chromium-reducing component (mass ratio of thiourea dioxide to sodium cyanoborohydride is 3:1), 10 wt% of antioxidant component (methacrylic acid), 40 wt% of grinding aid component (triethanolamine 20%, diethanol monoisopropanolamine 10%, modified calcium lignosulfonate 10%), and the balance of water. The preparation method of the composite chromium-reducing grinding aid comprises the following steps:
s1, adding chromium reduction components (thiourea dioxide and sodium cyanoborohydride) and water at normal temperature, and stirring at 100rpm for 5 min;
s2, adding antioxidant component (methacrylic acid), stirring at 100rpm for 8 min; and (3) keeping the stirring state, adding grinding aid components (triethanolamine and diethanol monoisopropanolamine), adding the grinding aid components (modified calcium lignosulphonate), and continuously stirring at 100rpm for 20min to obtain the finished product of the composite chromium-reducing grinding aid. Same as in example 1.
Example 3
The raw materials of the composite chromium-reducing grinding aid provided by the embodiment comprise 30 wt% of chromium-reducing component (mass ratio of thiourea dioxide to sodium cyanoborohydride is 2:1), 5 wt% of antioxidant component (formamide), 20 wt% of grinding aid component (10% of diethanol monoisopropanolamine, 8% of triisopropanolamine, 2% of modified calcium lignosulfonate), and the balance of water. The preparation method of the composite chromium-reducing grinding aid is the same as that of the embodiment 1.
The preparation method of the composite chromium-reducing grinding aid comprises the following steps:
s1, adding chromium reduction components (thiourea dioxide and sodium cyanoborohydride) and water at normal temperature, and stirring at 100rpm for 5 min;
s2, adding an antioxidant component (formamide), and stirring at 100rpm for 8 min; and (3) keeping the stirring state, adding grinding aid components (diethanol monoisopropanolamine and triisopropanolamine) firstly, then adding the grinding aid components (modified calcium lignosulphonate), and continuing stirring at 100rpm for 20min to obtain the finished product of the composite chromium-reducing grinding aid. Same as in example 1.
Example 4
The raw materials of the composite chromium-reducing grinding aid provided by the embodiment comprise 30 wt% of chromium-reducing components (mass ratio of thiourea dioxide to sodium cyanoborohydride is 3:2), 8 wt% of antioxidant components (mass ratio of formamide to sulfosalicylic acid is 1:1), 20 wt% of grinding-aid components (10% of diethanol monoisopropanolamine, 8% of triisopropanolamine, 2% of modified calcium lignosulfonate), and the balance of water. The preparation method of the composite chromium-reducing grinding aid is the same as that of the embodiment 1.
The preparation method of the composite chromium-reducing grinding aid comprises the following steps:
s1, adding chromium reduction components (thiourea dioxide and sodium cyanoborohydride) and water at normal temperature, and stirring at 100rpm for 5 min;
s2, adding an antioxidant component (the mass ratio of formamide to sulfosalicylic acid is 1:1), and stirring at 100rpm for 8 min; and (3) keeping the stirring state, adding grinding aid components (diethanol monoisopropanolamine and triisopropanolamine) at first, then adding the grinding aid components (modified calcium lignosulphonate), and continuously stirring at 100rpm for 20min to obtain the finished product of the composite chromium-reducing grinding aid. Same as in example 1.
Example 5
The raw materials of the composite chromium-reducing grinding aid provided by the embodiment comprise 25 wt% of chromium-reducing component (sodium cyanoborohydride), 8 wt% of antioxidant component (the mass ratio of formamide to methacrylic acid is 1:1), 30 wt% of grinding aid component (20 wt% of triethanolamine, 7 wt% of diethanol monoisopropanolamine, 3 wt% of modified calcium lignosulfonate), and the balance of water.
The preparation method of the composite chromium-reducing grinding aid provided by the embodiment comprises the following steps:
s1, adding a chromium reduction component (sodium cyanoborohydride) and water at normal temperature, and stirring at 100rpm for 5 min;
s2, adding an antioxidant component (the mass ratio of formamide to methacrylic acid is 1:1), and stirring at 100rpm for 8 min; and (3) keeping the stirring state, adding grinding aid components (triethanolamine and diethanol monoisopropanolamine), then adding the grinding aid components (modified calcium lignosulfonate), and continuously stirring at 100rpm for 20min to obtain the finished product of the composite chromium-reducing grinding aid.
Comparative example 1
The composite chromium-reducing grinding aid provided by the comparative example comprises 25 wt% of chromium-reducing component (the mass ratio of ferrous sulfate to stannous sulfate is 4:1), 8 wt% of antioxidant component (ascorbic acid), 30 wt% of grinding aid component (triethanolamine 20 wt%, diethanol monoisopropanolamine 7 wt%, and modified calcium lignosulfonate 3 wt%), and the balance of water. The preparation method of the composite chromium-reducing grinding aid comprises the following steps:
s1, adding chromium reducing components (ferrous sulfate, stannous sulfate and water) at normal temperature, and stirring at 100rpm for 5 min;
s2, adding antioxidant component (ascorbic acid), stirring at 100rpm for 8 min; and (3) keeping the stirring state, adding grinding aid components (triethanolamine and diethanol monoisopropanolamine), then adding the modified calcium lignosulfonate, and continuously stirring at 100rpm for 20min to obtain the finished product of the composite chromium-reducing grinding aid.
Comparative example 2
The composite chromium-reducing grinding aid provided by the comparative example comprises 15 wt% of chromium-reducing component (mass ratio of thiourea dioxide to sodium borohydride is 2:1), 40 wt% of grinding aid component (triethanolamine 20%, diethanol monoisopropanolamine 10%, modified calcium lignosulfonate 10%), and the balance of water.
The preparation method of the composite chromium-reducing grinding aid provided by the comparative example comprises the following steps:
s1, adding chromium reduction components (thiourea dioxide and sodium borohydride) and water at normal temperature, and stirring at 100rpm for 5 min;
and S2, keeping the stirring state, adding grinding aid components (triethanolamine and diethanol monoisopropanolamine), adding the modified calcium lignosulfonate, and continuously stirring at 100rpm for 20min to obtain the finished product of the composite chromium-reducing grinding aid.
Comparative example 3
The comparison example adopts a commercially available liquid chromium reducing agent as a comparison, and the main component is a suspension liquid formed by uniformly mixing antimony trioxide, stannous sulfate and water, and the price is about 12000 yuan/ton.
Application example: comparison of the Properties of the finished products prepared in the examples and comparative examples
The finished products prepared in the above examples and comparative examples were subjected to comparative tests for physical properties. 9 equal parts of the Wawa stone P.O42.5 Portland cement, wherein 8 parts of blank cement are respectively mixed into finished products corresponding to the samples in examples 1-5 and comparative examples 1-3, the mixing amount is 0.05%, and the cement paste fluidity is determined according to the determination method of the cement paste fluidity in GB/T8077-2012 concrete additive homogeneity test method. And (3) measuring the water consumption, setting time and stability of the standard consistency of the cement according to GB/T1346-2011 inspection method for the water consumption, setting time and stability of the standard consistency of the cement. The strength of the cement mortar is determined according to GB/T17671-1999 method for testing the strength of cement mortar (ISO method). The results of the physical property measurements are shown in Table 1.
TABLE 1 physical Property results of Cement mortar incorporating the finished products of examples 1-5 and comparative examples 1-3
Setting the mass ratio of cement: clinker 76% (purchased from general purpose portland cement clinker produced by Yangxinngwoshi cement Co., Ltd.), slag 10% (purchased from Wu steel, particle size less than 10mm), fly ash 2.5% (purchased from Huangshi Xisaishan power plant, level II), desulfurized gypsum 4.5% (purchased from power plant of Ku shop, Ohio) and limestone 7% (purchased from Yangxinngwoshi stone mine to New Material Co., Ltd.). The materials are the same uniform sample, the small grinding test is carried out on the materials in 9 groups according to the same proportion, the total weight of each group of materials is 5kg, the finished products prepared in the examples 1-5 and the comparative examples 1-3 are respectively added according to the doping amount of 0.05 percent and are uniformly mixed, and a blank comparative example (namely no grinding aid is added) is arranged; grinding for 28min in a standard test mill with phi 500mm multiplied by 500mm respectively to obtain 9 groups of small-grinding cement, and carrying out a grinding-aid effect comparison test, wherein the results are shown in the following table 2.
TABLE 2 physical Property results for millbase cements incorporating the finished products of examples 1-5 and comparative examples 1-3
The test of the small-grinding cement under different conditions is carried out according to GB 31893-2015 limit and determination method for water-soluble chromium (VI) in the cement to determine the content of the water-soluble hexavalent chromium in the cement. The hexavalent chromium content of the cement is shown in table 3 below.
TABLE 3 test results of hexavalent chromium content of cement of small milled cements blended with the finished products of examples 1-5 and comparative examples 1-3
As can be seen from the data in tables 1-3, the composite chromium-reducing grinding aid prepared in the examples has the advantages of obviously improving the mechanical strength, the flowability and other properties of cement and having good grinding-aiding effect. After the composite chromium-reducing grinding aid of the examples 1-5 is added, the water-soluble chromium (VI) in the cement is obviously reduced, the higher the proportion of the chromium-reducing component is, the larger the chromium-reducing amplitude is, and the content of hexavalent chromium does not rebound obviously under the high-temperature condition and after long-term storage, which shows that the chemical stability is good.
The chromium reducing agent obtained in the comparative example 1 adopts conventional ferrous sulfate and stannous sulfate, the reduction effect is not as good as that of the chromium reducing agent obtained in the examples 1-5, and obvious rebound occurs particularly under high temperature conditions and after long-term storage; comparative example 2, in which no antioxidant component was added, was identical to the other components of example 2, and the high temperature condition and long-term storage of hexavalent chromium were reflected in the rebound of example 2; the chromium-reducing effect of the comparative example 3 is close to that of the example 5, but the stability is slightly poor, the cost is too high and exceeds 10000 Yuan/ton, and the cost of the composite chromium-reducing grinding aid of the examples 1-5 is 5000-. In summary, the compound chromium-reducing grinding aid has a scientific and reasonable formula, each component is absent, and the components are matched with each other to play a role together, so that an excellent chromium-reducing grinding aid effect is achieved.
The composite chromium-reducing grinding aid has the advantages of good chromium-reducing effect, no rebound of hexavalent chromium under high temperature, basically stable water-soluble chromium (VI) after long-term storage, better effect than common chromium-reducing agents in the market, no adverse effect on the stability of cement, water consumption for standard consistency, net slurry fluidity and setting time, obviously increased cement strength, good grinding-aid effect, capability of replacing the chromium-reducing agent and the cement grinding aid at the same time, low production cost and contribution to popularization and application.
The practice of the present invention has been described in detail with reference to the foregoing detailed description, but the invention is not limited to the specific details of the foregoing embodiment. Within the scope of the claims and the technical idea of the invention, a number of simple modifications and changes can be made to the technical solution of the invention, and these simple modifications are within the scope of protection of the invention.
Claims (9)
1. The composite chromium-reducing grinding aid is characterized in that raw materials comprise 15-30 wt% of chromium-reducing component, 5-10 wt% of antioxidant component, 20-40 wt% of grinding aid component and the balance of water; the chromium reducing component is thiourea dioxide and/or sodium cyanoborohydride.
2. The composite chromium-reducing grinding aid as claimed in claim 1, wherein the raw materials comprise 25 wt% of chromium-reducing component, 8 wt% of antioxidant component, 30 wt% of grinding aid component, and the balance of water.
3. The composite chromium-reducing grinding aid as claimed in claim 1 or 2, wherein the mass ratio of thiourea dioxide to sodium cyanoborohydride is 3 (1-2).
4. The composite chromium-reducing grinding aid as claimed in claim 3, wherein the mass ratio of thiourea dioxide to sodium cyanoborohydride is 2: 1.
5. The composite chromium-reducing grinding aid according to claim 1, wherein the antioxidant component is one or more of formamide, methacrylic acid and sulfosalicylic acid.
6. The composite chromium-reducing grinding aid of claim 1, wherein the grinding aid component consists of alcohol amine and modified lignosulfonate, wherein the modified lignosulfonate accounts for 2-10% of the total mass of the composite chromium-reducing grinding aid; the preparation method of the modified lignosulfonate comprises the following steps:
p1, dissolving 50-60 parts by weight of lignosulfonate in water, heating to 75-85 ℃, adjusting the pH value of the solution to 9-10, and stirring for 20-35 min;
p2, adding dilute nitric acid into the mixed solution obtained in the step P1 to adjust the pH value of the solution to 8-9, and then adding 5-10 parts by weight of H 2 O 2 Or KMnO 4 And 1-2 parts by weight of FeO or CuO, reacting for 0.5-1 h;
p3, adding 40-50% by mass of formaldehyde aqueous solution and fatty amine into the mixed solution obtained in the step P2, wherein the total parts of the formaldehyde aqueous solution and the fatty amine are 20-30 parts by weight, the ratio of the mass of the formaldehyde to the mass of the fatty amine is 1:1, and reacting for 1-1.5 h;
p4, adding 3-5 parts by weight of formaldehyde aqueous solution with the mass fraction of 40-50% for reaction for 0.5-1h, finally adding 3-6 parts by weight of sodium carboxymethylcellulose and 2-4 parts by weight of sodium sulfate, stirring for 10-30min, and cooling to obtain the modified lignosulfonate.
7. The composite chromium-reducing grinding aid according to claim 6, wherein the alcohol amine is one or more of triethanolamine, triisopropanolamine, tripropylene glycol, diethanol monoisopropanolamine and monoethanol diisopropanolamine.
8. The preparation method of the composite chromium-reducing grinding aid as claimed in claim 1, characterized by comprising the following steps:
s1, adding the grinding aid component and water at normal temperature, and stirring uniformly;
s2, adding the antioxidant component and stirring uniformly; and keeping stirring, adding the chromium-reducing component, and continuously stirring uniformly to obtain a finished product of the composite chromium-reducing grinding aid.
9. The preparation method of the composite chromium-reducing grinding aid as claimed in claim 8, wherein the stirring rotation speeds of steps S1 and S2 are both 60-150 rpm; the stirring time in the step S1 is 3-6min, the stirring time after the antioxidant component is added in the step S2 is 5-10min, and the stirring time after the chromium-reducing component is added is 15-30 min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210662687.XA CN115093152B (en) | 2022-06-13 | 2022-06-13 | Composite chromium-reducing grinding aid and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210662687.XA CN115093152B (en) | 2022-06-13 | 2022-06-13 | Composite chromium-reducing grinding aid and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115093152A true CN115093152A (en) | 2022-09-23 |
| CN115093152B CN115093152B (en) | 2023-06-16 |
Family
ID=83291782
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210662687.XA Active CN115093152B (en) | 2022-06-13 | 2022-06-13 | Composite chromium-reducing grinding aid and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115093152B (en) |
Citations (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4454237A (en) * | 1983-01-27 | 1984-06-12 | Corning Glass Works | Organic-inorganic composites containing synthetic mica |
| JP2004210589A (en) * | 2002-12-27 | 2004-07-29 | Nippon Shiika Kk | Cement dispersant and concrete composition containing the dispersant |
| CN1974467A (en) * | 2006-12-07 | 2007-06-06 | 华南理工大学 | Lignosulfonate series air entraining and water reducing admixture for concrete and its prepn process and application |
| JP2009263224A (en) * | 2008-04-04 | 2009-11-12 | Maruo Calcium Co Ltd | Colloidal calcium carbonate filler, method for producing the same, and resin composition blended with the filler |
| CN101927153A (en) * | 2009-06-24 | 2010-12-29 | 上海纳欣生物科技有限公司 | Novel high-efficiency dechromisation agent and preparation method thereof |
| CN102050594A (en) * | 2009-11-06 | 2011-05-11 | 山东宏艺科技股份有限公司 | Herbaceous plant lignin cement grinding aid and preparation method thereof |
| US20130296544A1 (en) * | 2011-01-26 | 2013-11-07 | Gunze Limited | Method for producing hydrophilized cellulose fiber, and method for reducing oxidized cellulose fiber |
| CN103553456A (en) * | 2013-10-15 | 2014-02-05 | 句容市睿远科技有限公司 | Self-compaction high-performance concrete for high-speed rail construction |
| CN104909604A (en) * | 2015-05-27 | 2015-09-16 | 湖州华仑助剂科技有限公司 | Composite cement grinding aid |
| CN105924029A (en) * | 2016-04-21 | 2016-09-07 | 张伟 | Liquid cement additive for reducing content of water-soluble Cr<6+> in cement |
| FR3056601A1 (en) * | 2016-09-28 | 2018-03-30 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | PROCESS FOR MANUFACTURING NUCLEAR COMPONENT WITH METAL SUBSTRATE BY DLI-MOCVD |
| CN108676353A (en) * | 2018-05-24 | 2018-10-19 | 东阳市特意新材料科技有限公司 | A kind of heat resistant polyamide plastics and preparation method thereof |
| CN110054806A (en) * | 2019-04-26 | 2019-07-26 | 金旸（厦门）新材料科技有限公司 | A kind of antioxidant system and high-temperature-resnylont nylont material and application and LED support |
| CN111635160A (en) * | 2020-06-15 | 2020-09-08 | 安徽海螺新材料科技有限公司 | Composite chromium-reducing cement grinding aid and preparation method thereof |
| WO2020189802A1 (en) * | 2019-03-15 | 2020-09-24 | 유한회사 한국신기술 | Antioxidant, comprising cyano-carboxy group composite free from sulfur (s) component, for preventing oxidation of trivalent chromium ions to divalent chromium ions, and trivalent chromium electroplating solution comprising same |
| CN111875278A (en) * | 2020-07-13 | 2020-11-03 | 南京神仂建材科技有限公司 | Efficient cement chromium-removing grinding aid |
| CN113003981A (en) * | 2021-04-19 | 2021-06-22 | 武汉三源特种建材有限责任公司 | Superfine composite mineral admixture grinding aid and preparation method thereof |
| CN113480219A (en) * | 2021-07-15 | 2021-10-08 | 内蒙古宏尔高新材料科技有限公司 | Chromium reducing agent for reducing water-soluble chromium (VI) in cement and preparation method thereof |
-
2022
- 2022-06-13 CN CN202210662687.XA patent/CN115093152B/en active Active
Patent Citations (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4454237A (en) * | 1983-01-27 | 1984-06-12 | Corning Glass Works | Organic-inorganic composites containing synthetic mica |
| JP2004210589A (en) * | 2002-12-27 | 2004-07-29 | Nippon Shiika Kk | Cement dispersant and concrete composition containing the dispersant |
| CN1974467A (en) * | 2006-12-07 | 2007-06-06 | 华南理工大学 | Lignosulfonate series air entraining and water reducing admixture for concrete and its prepn process and application |
| JP2009263224A (en) * | 2008-04-04 | 2009-11-12 | Maruo Calcium Co Ltd | Colloidal calcium carbonate filler, method for producing the same, and resin composition blended with the filler |
| CN101927153A (en) * | 2009-06-24 | 2010-12-29 | 上海纳欣生物科技有限公司 | Novel high-efficiency dechromisation agent and preparation method thereof |
| CN102050594A (en) * | 2009-11-06 | 2011-05-11 | 山东宏艺科技股份有限公司 | Herbaceous plant lignin cement grinding aid and preparation method thereof |
| US20130296544A1 (en) * | 2011-01-26 | 2013-11-07 | Gunze Limited | Method for producing hydrophilized cellulose fiber, and method for reducing oxidized cellulose fiber |
| CN103553456A (en) * | 2013-10-15 | 2014-02-05 | 句容市睿远科技有限公司 | Self-compaction high-performance concrete for high-speed rail construction |
| CN104909604A (en) * | 2015-05-27 | 2015-09-16 | 湖州华仑助剂科技有限公司 | Composite cement grinding aid |
| CN105924029A (en) * | 2016-04-21 | 2016-09-07 | 张伟 | Liquid cement additive for reducing content of water-soluble Cr<6+> in cement |
| FR3056601A1 (en) * | 2016-09-28 | 2018-03-30 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | PROCESS FOR MANUFACTURING NUCLEAR COMPONENT WITH METAL SUBSTRATE BY DLI-MOCVD |
| CN108676353A (en) * | 2018-05-24 | 2018-10-19 | 东阳市特意新材料科技有限公司 | A kind of heat resistant polyamide plastics and preparation method thereof |
| WO2020189802A1 (en) * | 2019-03-15 | 2020-09-24 | 유한회사 한국신기술 | Antioxidant, comprising cyano-carboxy group composite free from sulfur (s) component, for preventing oxidation of trivalent chromium ions to divalent chromium ions, and trivalent chromium electroplating solution comprising same |
| CN110054806A (en) * | 2019-04-26 | 2019-07-26 | 金旸（厦门）新材料科技有限公司 | A kind of antioxidant system and high-temperature-resnylont nylont material and application and LED support |
| CN111635160A (en) * | 2020-06-15 | 2020-09-08 | 安徽海螺新材料科技有限公司 | Composite chromium-reducing cement grinding aid and preparation method thereof |
| CN111875278A (en) * | 2020-07-13 | 2020-11-03 | 南京神仂建材科技有限公司 | Efficient cement chromium-removing grinding aid |
| CN113003981A (en) * | 2021-04-19 | 2021-06-22 | 武汉三源特种建材有限责任公司 | Superfine composite mineral admixture grinding aid and preparation method thereof |
| CN113480219A (en) * | 2021-07-15 | 2021-10-08 | 内蒙古宏尔高新材料科技有限公司 | Chromium reducing agent for reducing water-soluble chromium (VI) in cement and preparation method thereof |
Non-Patent Citations (4)
| Title |
|---|
| 李祥彦等: "锡基化工材料消除水泥Cr~(6+)应用前景分析", 《中国水泥》 * |
| 梁浩楣等: "木质素系高性能引气减水剂 GCL1-D 的性能和作用机理研究", 《混凝土》 * |
| 王天贵;田雅洁;: "三价铬氧化方法比较研究", 无机盐工业 * |
| 陈秀华;宋海武;: "复合助磨剂对水泥性能影响的研究", 新世纪水泥导报 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115093152B (en) | 2023-06-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105271918A (en) | Cement grinding aid and preparation method thereof | |
| EP1752428B1 (en) | Method for reducing chromium (VI) in cement | |
| CN107235649B (en) | A kind of cement grinding aid and preparation method thereof | |
| CN104446111A (en) | Cement grinding aid | |
| CN111646727B (en) | Composite cement additive | |
| CN102503233A (en) | Novel liquid cement grinding aid and preparation method thereof | |
| CN104496251A (en) | Liquid hexavalent chromium reducing agent and preparation method thereof, cement and preparation method thereof | |
| CN103274632B (en) | Reinforced cement grinding aid and preparation method thereof | |
| CN113003981B (en) | Superfine composite mineral admixture grinding aid and preparation method thereof | |
| CN110218017A (en) | A kind of new modified cement grinding aid and preparation method thereof | |
| CN113480219A (en) | Chromium reducing agent for reducing water-soluble chromium (VI) in cement and preparation method thereof | |
| CN104891844B (en) | A kind of cement grinding aid | |
| CN110330255B (en) | Coagulation-promoting liquid grinding aid and preparation method thereof | |
| CN112456855A (en) | Liquid grinding aid for improving later strength of cement and preparation method thereof | |
| CN106380110A (en) | Graphene oxide modified cement grinding aid and preparation method thereof | |
| CN111087189A (en) | Hexavalent chromium reducing agent and preparation method thereof | |
| CN108821628A (en) | A kind of no chlorine high-early (strength) cement grinding aid and preparation method thereof | |
| CN109336458B (en) | Cement grinding aid | |
| CN109761518A (en) | A kind of complex cement chromium removal grinding aid and preparation method thereof | |
| CN111807749B (en) | Hexavalent chromium reducing agent and preparation method thereof | |
| CN115093152B (en) | Composite chromium-reducing grinding aid and preparation method thereof | |
| CN112062487B (en) | Additive for cement clinker production | |
| CN112645628A (en) | Formula and preparation process of novel powder cement grinding aid | |
| CN106118764A (en) | A kind of slurries additive agent | |
| CN108690980A (en) | A kind of galvanized steel plain sheet trivalent chromium passivator concentrate and preparation method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |