CN114804678B

CN114804678B - Composite cement raw material grinding-aiding coal-saving agent and preparation method and application thereof

Info

Publication number: CN114804678B
Application number: CN202210217028.5A
Authority: CN
Inventors: 史才军; 裴敏
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-03-07
Filing date: 2022-03-07
Publication date: 2023-02-10
Anticipated expiration: 2042-03-07
Also published as: CN114804678A

Abstract

A composite cement raw material grinding-aid coal-saving agent, a preparation method and an application thereof are disclosed, wherein the composite cement raw material grinding-aid coal-saving agent is prepared from the following components: crack expanding agent, combustion improver, composite oxidant, sulfur fixing agent, emulsifier and penetrant. The invention also discloses a preparation method of the composite cement raw material grinding-aiding coal-saving agent. When cement raw materials are ground, the composite raw material grinding-aid coal-saving agent is doped into the cement raw materials, so that the grinding-aid effect can be achieved, the machine-hour yield of the raw materials is increased, the grinding efficiency is improved, coal consumption can be saved, and the emission of dust and sulfur dioxide is reduced; the preparation method is simple and suitable for large-scale industrial production.

Description

Composite cement raw material grinding-aiding coal-saving agent and preparation method and application thereof

Technical Field

The invention relates to a grinding-aiding coal-saving agent for cement raw materials, a preparation method and application thereof, in particular to a composite grinding-aiding coal-saving agent for cement raw materials, a preparation method and application thereof.

Background

The production process of cement is generally known as 'two-mill one-burning', wherein in the process of converting cement raw materials into clinker, most of energy consumed by the raw material vertical mill is converted into sound energy and heat energy, and the problem of low energy utilization rate is very prominent. The cement kiln has high demand on coal, but the effective utilization rate is very low, and the cement kiln can generate waste gas and dust pollution containing a large amount of carbon monoxide and sulfide while consuming a large amount of coal resources, thereby having serious influence on the environment. In the cement production process, how to improve the efficiency of raw material grinding and clinker sintering is a key topic for improving the effective utilization rate of coal and reducing the energy and resource consumption of the cement production industry.

Hitherto, additives used in cement production mainly include coal-saving combustion improver, cement grinding aid, sulfur fixing agent and the like, and are respectively aimed at the fields of coal combustion supporting, clinker grinding, cement kiln flue gas desulfurization and the like in the cement clinker firing process. However, the conventional grinding aid is not suitable for vertical grinding of raw materials, and the grinding aid and coal saving efficiency of the cement raw materials are difficult to be improved simultaneously. In addition, the acceptance of the existing raw material grinding aid and coal saving agent is not high, the use effect is poor, and the method mainly comprises the following reasons: (1) The grinding and coal saving efficiency is not ideal, and even the brought benefits can not offset the cost of the additive; (2) The used raw material grinding aid and coal saving agent are powder, which is very easy to cause inaccurate metering and error; (3) The mixing amount of the additive is larger, generally more than 1 percent, and the use cost is high; (4) A large amount of chemical hazardous waste is used in part of additives, and the additives cause harm to human health and cement quality in the production, transportation and use processes.

CN 113800796A discloses a cement raw material additive and a preparation method thereof, wherein the cement raw material additive comprises the following raw materials by mass percent: 10 to 17 percent of raw material decomposition accelerator, 13 to 16 percent of coal saving agent, 6 to 9 percent of grinding-aid reinforcing agent, 10 to 14 percent of desulfurization active agent and 0.1 to 0.3 percent of dispersant; the balance of water, the total amount is 100%; the raw material decomposition accelerator is one or a mixture of oxalic acid, citric acid, sodium acetate or potassium acetate; the coal saving agent is one or a mixture of a plurality of polyalcohol polymers, hydrogen peroxide or glycol; the grinding aid reinforcing agent is one or a mixture of triethanolamine, glycerol, triisopropanolamine and diethanolamine; the dispersant is one or a mixture of cetyl trimethyl ammonium bromide and lauryl sodium sulfate. The cement raw material additive introduces a large amount of acidic substances in cement production, has negative effects on the quality control of cement clinker, has low coal saving rate and the rise range of the raw material output per hour, has unsatisfactory coal saving efficiency, can not offset the cost of the raw material grinding aid due to the benefit brought by coal saving, has limited effect on improving the quality of the cement clinker, and is not suitable for large-scale popularization.

CN104119982A discloses a coal saving agent for rotary kiln clinker firing of cement clinker and a preparation method thereof, wherein the coal saving agent is prepared by dealkalizing and/or drying calcium silicate slag, and the coal saving agent contains dicalcium silicate (2CaO. SiO) ₂ ) (ii) a The total weight of silicon dioxide and calcium oxide in the coal saving agent is 70-77 wt%; the density of the coal saving agent is 2.9-3.1 g/cm ³ The bulk volume weight is 0.9-1.3 g/cm ³ The median particle diameter is 25-30 mu m; and based on the total weight of the coal saving agent, with Na ₂ And the alkali content of the coal saving agent is less than 1wt% and the water content of the coal saving agent is less than 5wt% in terms of the amount of O. The preparation steps of the coal saving agent are various, the preparation conditions are complex, the reaction is carried out under the condition of high-temperature water, and the dehydration operation is carried out through a filter press, so that the technical parameters are difficult to control; the obtained finished product is solid, is not uniformly dispersed in use and has low practicability.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects in the prior art and provide the composite raw material grinding-aid coal-saving agent which not only can play a role in grinding aid of cement raw materials, improve the yield of the raw materials in grinding, but also can save coal, reduce the emission of dust and sulfur dioxide and reduce power consumption.

The invention further aims to solve the technical problem of providing a preparation method of the composite raw material grinding-aid coal saving agent, which is simple and convenient to operate.

The technical scheme adopted by the invention for solving the technical problems is that the composite raw material grinding-assisted coal saving agent is prepared from the following components: crack expanding agent, combustion improver, composite oxidant, sulfur fixing agent, emulsifier and penetrant.

Further, the mass fraction of the components is as follows: 8-12% of crack expanding agent, 5-10% of combustion improver, 15-25% of oxidant, 5-8% of sulfur-fixing agent, 5-15% of emulsifier and 35-50% of penetrant.

Further, the mass fraction of the components is preferably: 10% of crack expanding agent, 8% of combustion improver, 21% of composite oxidant, 6% of sulfur fixing agent, 10% of emulsifier and 45% of penetrating agent.

Further, the crack propagation agent includes, but is not limited to, a mixture of ethylene glycol, formamide, aminoethanol, triethanolamine, and diethanolisopropanolamine.

Further, in the crack propagation agent, the mixing ratio of ethylene glycol, formamide, aminoethanol, triethanolamine and diethanolisopropanolamine is preferably (1.5-2.5): 0.4-0.9): 0.5-1.0): 1.5-2.0): 1.

The ethylene glycol, the formamide and the aminoethanol are liquid organic compounds with large surface tension, can be adsorbed on the surfaces of material particles and in new and old cracks, reduce the free energy of the surfaces of the particles, expand the cracks and prevent the cracks from compounding under the action of mechanical force, change the structures of the surfaces of the particles, reduce the strength and hardness of the particles, enable the particles to be crushed more easily, and improve the crushing efficiency of cement raw materials. Triethanolamine and diethanol monoisopropanolamine are used as surfactants, which have a balancing effect on charges on the surfaces of particles, can remarkably reduce or eliminate adhesion and agglomeration among the particles, increase the fluidity of the particles and improve the grinding efficiency.

Further, the combustion improver includes, but is not limited to, a mixture of ammonium persulfate and sodium chloride.

Furthermore, the mixing ratio of ammonium persulfate and sodium chloride in the combustion improver is (1.0-2.0): 1.

Wherein the sodium chloride can be chemical waste or industrial salt containing more than 85 percent of sodium chloride. The ammonium persulfate can release oxygen containing ozone when meeting water, and oxygen can be decomposed when heating, so that the combustion-supporting effect is good.

Further, the oxidant includes but is not limited to one or more of potassium chloride, potassium chlorate, potassium permanganate, ammonium perchlorate and ferric chloride; preferably a composite oxidant prepared by mixing and compounding more than two oxidants.

In the combustion process, the strong oxidant can increase the concentration of oxygen, continuously decompose the oxygen at different temperatures, utilize micro-explosion and collision mechanisms, make the temperature and oxygen distribution in the hearth more uniform, and make the combustible in the fire coal quickly and fully burn, and produce ion exchange combustion reaction under the action of catalyst and modifier, make the traditional vertical kiln raw meal change from the surface and combustion mode to the inside and outside combustion together, reduce the heat loss brought away by the incomplete combustion of the coal in the kiln.

Further, the sulfur-fixing agent includes, but is not limited to, a mixture of sodium carbonate, calcium oxide and potassium carbonate.

Furthermore, the mixing ratio of the sodium carbonate, the calcium oxide and the potassium carbonate in the sulfur fixing agent is (1.0-1.5): (1.0-1.5): 1.

The sulfur-fixing agent promotes sulfur dioxide generated by coal combustion to be solidified and left in coal cinder to generate sulfate solid, and the discharge amount of harmful gas is reduced.

Further, the emulsifier is alkylphenol ethoxylates and/or glycerol; the penetrant may be a mixture of industrial wastewater containing organic acids and water. The organic acid can reduce the decomposition surface activation energy of calcium carbonate, further reduce the decomposition temperature of calcium carbonate, accelerate the decomposition of calcium carbonate and play a certain role in grinding aid.

Furthermore, the mass ratio of the industrial wastewater containing organic acid to water in the penetrant is 1 (2~3).

Further, the organic acid is one or more of oxalic acid, glycolic acid, substituted carboxylic acid and sulfanilic acid.

Furthermore, the composite raw material grinding-aiding coal-saving agent is in a liquid state.

The application of the composite raw material grinding-aid coal-saving agent comprises the following steps: the mixing amount of the composite raw material grinding-assisting coal-saving agent is 0.03-0.05% of the total mass of the raw material and coal.

The invention further solves the technical problem by adopting the technical scheme that the preparation method of the composite raw material grinding-aid coal saving agent comprises the following steps:

(1) Adding the crack expanding agent, the combustion improver and the emulsifier into the liquid penetrant, uniformly stirring, and standing to obtain a mixture;

(2) And (2) adding an oxidant and a sulfur-fixing agent into the mixture obtained in the step (1), and uniformly mixing to obtain the composite raw material grinding-aid coal-saving agent.

In the step (1), the standing time is 3 to 6h, preferably 4 to 5h.

Compared with the prior art, the invention has the following beneficial effects: (1) In the cement raw material grinding and firing processes, the composite raw material grinding-assisted coal saving agent provided by the invention can be used for greatly improving the output of the raw material vertical mill per unit time, improving the grinding efficiency, improving the quality of molded coal, improving the combustion condition of a furnace body, enhancing the air permeability of a coal bed, prolonging the open fire time, increasing the height and density of flame, solving the problem of insufficient combustion of inferior coal, remarkably improving the combustion efficiency of coal, achieving the effects of energy conservation and emission reduction, enabling the inferior coal which is not easy to combust to achieve the combustion effect of high-quality coal, and generating the economic benefits of superior coal and less superior coal; (2) The composite raw material grinding-aid coal-saving agent can also reduce the discharge amount of smoke dust, improve the heat conduction efficiency, fix sulfur and reduce smoke, reduce the discharge of pollutant gases such as dioxide and the like, and reduce environmental pollution, thereby simultaneously achieving the purposes of grinding aid, combustion supporting, sulfur fixing and energy saving and achieving multiple purposes; by using the composite raw material grinding-assisted coal saving agent, the yield of the raw material grinding for a bench is improved by 8-15%, and the comprehensive coal saving rate is improved by 15-20%.

Detailed Description

The present invention will be further described with reference to the following specific examples.

Example 1

The composite raw material grinding-aid coal-saving agent is prepared from the following components: crack expanding agent, combustion improver, composite oxidant, sulfur fixing agent, emulsifier and penetrant; in the crack expanding agent, the mixing ratio of ethylene glycol, formamide, aminoethanol, triethanolamine and diethanol monoisopropanolamine is 1.5; in the combustion improver, the mixing ratio of ammonium persulfate to sodium chloride is 1.5; the oxidant is a mixture of potassium chloride and potassium permanganate, and the mixing ratio is 1:1; in the sulfur fixing agent, the mixing ratio of sodium carbonate, calcium oxide and potassium carbonate is 1: 1.5:1; the emulsifier is a mixture of alkylphenol polyoxyethylene and glycerol, and the mixing ratio is 1:1; in the penetrant, the organic acid is oxalic acid. The specific proportions of the components in this example are shown in Table 1.

The preparation method of the composite raw material grinding-aid coal saving agent comprises the following steps:

(1) Adding a crack expanding agent, a combustion improver and an emulsifier into a liquid penetrant (the mass ratio of industrial wastewater to water is 3:7), uniformly stirring, and standing for 4 hours to obtain a mixture;

(2) And (2) adding the composite oxidant and the sulfur-fixing agent into the mixture obtained in the step (1), and uniformly mixing to obtain the composite raw material grinding-aid coal-saving agent.

The application comprises the following steps: the composite raw material grinding-aid coal-saving agent of the embodiment is mixed into cement raw materials and fire coal according to the proportion of 0.035 wt%.

And (3) detection: under the conditions of the same grinding time and the same heat supply, the yield of the raw material mill doped with the composite raw material grinding-aid coal-saving agent of the embodiment is improved by 14.8 percent, and the coal saving rate is 20.0 percent. The results are shown in Table 2.

Example 2~8

Compared with the example 1, the difference of the 2~8 composite raw material grinding-aid coal saving agent in the example is that the specific mixture ratio of each component of the composite raw material grinding-aid coal saving agent is different, and the preparation method and the detection method are the same as those in the example 1. The concrete proportion of each component of the compound raw material grinding-aid coal saving agent of example 2~8 is shown in table 1, and the detection result is shown in table 2.

Comparative example 1

The main difference of comparative example 1 compared to example 1 is the absence of crack-propagation agent, the same preparation method and the same detection method as in example 2. The specific proportions of the components are shown in Table 1. The results are shown in Table 3.

Comparative example 2

The main difference of comparative example 2 compared to example 1 is that the organic acid in the penetrant used was entirely replaced with citric acid, and the preparation method and the detection method were the same as those of example 1. The specific proportions of the components are shown in Table 1. The results are shown in Table 3.

Comparative example 3

Comparative example 3 is a raw material catalyst of the prior art purchased from environmental science ltd, nan chang di, lake, whose main component is organic acid salt, the mixing amount is 0.06%, and the use effect is shown in table 3.

As is clear from tables 1 and 3, the main difference of comparative example 1 compared with example 1 is that no crack extender is added, and the main difference of comparative example 2 is that all of the organic acid oxalic acid in the penetrant used is replaced with citric acid which also has an accelerating effect on the decomposition of calcium carbonate. Finally, the coal saving rate and the mill bench yield increasing rate of the raw material grinding-assisted coal saving agent respectively obtained in the comparative example 1 and the comparative example 2 are obviously lower than those of the composite raw material grinding-assisted coal saving agent in the example 1. Therefore, the crack extender in the composite raw material grinding-aid coal-saving agent is an essential component, and other components cannot be replaced randomly.

As can be seen from tables 1 and 2, compared with example 1, the main difference of example 2 is that the mass fraction of the crack extension agent is reduced to 3%, the amount of the penetrant is increased appropriately, the coal saving rate of the composite raw material grinding aid coal saving agent obtained in example 2 is 12.0%, the yield of a mill table is improved by 8.1%, both of which are significantly lower than those of example 1 (20.0%, 14.8%), and the preferable mass fraction of the crack extension agent is important for the composite raw material grinding aid coal saving agent of the invention.

As can be seen from tables 1 and 2, the main difference between example 3 and example 7 is that the mass fractions of the components of the composite raw grinding aid coal saving agent are partially adjusted and still fall within the preferred range of the present invention, compared with example 1, therefore, the coal saving rates of the composite raw grinding aid coal saving agents obtained in examples 3 and 7 are 18.6% and 14.0%, respectively, and the yield of the mill table is improved by 12.5% and 10.0%, respectively, which is also ideal.

As can be seen from tables 1 and 2, compared with example 1, the main differences between example 4 and example 5 are that the mass fraction of the composite oxidizing agent is reduced to 5% and 10%, the mass fraction of the penetrating agent is increased to 61% and 56%, the coal saving rate of the composite raw grinding aid obtained in example 4 and example 5 is 5.5% and 11.5%, respectively, the yield of the mill table is improved by 8.5% and 9.1%, both of which are significantly lower than those of example 1 (20.0%, 14.8%), and the preferred mass fractions of the composite oxidizing agent and the penetrating agent are also important for the composite grinding aid of the invention.

From tables 1 and 2, the main difference of example 6 is that the mass fraction of the crack extension agent is reduced to 3% and the mass fractions of the combustion improver and the composite oxidant are increased to 12% and 28%, respectively, which are not within the preferred mass fraction range of the components of the invention, and the coal saving rate and the mill stand yield of the composite raw grinding aid coal saving agent obtained in example 6 are not high, namely the coal saving rate is 14.5%, and the mill stand yield is improved by 7.8%, which are both significantly lower than those of example 1 (20.0%, 14.8%), and the mill stand yield is still lower than that of example 2. Therefore, the optimal mass fractions of the crack spreading agent, the combustion improver and the composite oxidant in the composite raw material grinding-aid coal-saving agent are also important, and even if the mass fractions of the combustion improver and the composite oxidant are increased, the comprehensive performance of the obtained composite raw material grinding-aid coal-saving agent is difficult to improve.

As can be seen from tables 1 and 2, the main difference between example 8 and example 1 is that increasing the mass fraction of the crack propagation agent to 15% and adjusting the mass fractions of the other components appropriately, the coal saving rate and mill stand yield of the composite raw grinding-aiding coal saving agent obtained are respectively 13.7% and 12.0%, which is also significantly lower than example 1 (20.0%, 14.8%). Moreover, comparing the example 1 with the example 2, and comparing the example 4~6 with the example 8, it can be seen that for the composite raw material grinding aid coal saving agent of the present invention, the components are related to each other, and if the composite raw material grinding aid coal saving agent is intended to improve the coal saving rate and the yield of the raw material grinding table at the same time, the selection of the mass fraction of each component is important.

Claims

1. A composite raw material grinding-assisted coal saving agent is characterized by being prepared from the following components: crack expanding agent, combustion improver, composite oxidant, sulfur fixing agent, emulsifier and penetrant;

the mass fraction of each component is as follows: 8-12% of crack expanding agent, 5-10% of combustion improver, 15-25% of oxidant, 5-8% of sulfur fixing agent, 5-15% of emulsifier and 35-50% of penetrating agent;

the crack expanding agent is a mixture of glycol, formamide, aminoethanol, triethanolamine and diethanol monoisopropanolamine;

the combustion improver is a mixture of ammonium persulfate and sodium chloride;

the oxidant is one or more of potassium chloride, potassium chlorate, potassium permanganate, ammonium perchlorate and ferric chloride;

the sulfur-fixing agent is a mixture of sodium carbonate, calcium oxide and potassium carbonate;

the penetrating agent is a mixture of industrial wastewater containing organic acid and water; the organic acid is one or more of oxalic acid, glycolic acid, substituted carboxylic acid and sulfanilic acid.

2. The composite raw material grinding-aiding coal-saving agent as claimed in claim 1, wherein the emulsifier is alkylphenol ethoxylates and/or glycerol.

3. The composite raw material grinding-aid coal-saving agent as claimed in claim 1 or 2, wherein the mass ratio of the industrial wastewater containing organic acid to water in the penetrant is 1 to 2-3.

4. A method for preparing a composite raw material grinding aid coal saving agent as claimed in any one of claims 1~3, comprising the steps of:

5. The use of the composite raw material grinding-aid coal-saving agent according to any one of claims 1~3, wherein the mixing amount of the composite raw material grinding-aid coal-saving agent is 0.03 to 0.05 percent of the total mass of raw material and coal.