CN113368971A

CN113368971A - Method for changing pulping process of rod mill

Info

Publication number: CN113368971A
Application number: CN202110654657.XA
Authority: CN
Inventors: 蒋峰; 闫家兴
Original assignee: Jiangsu Hengfeng Annex Polytron Technologies Inc
Current assignee: Jiangsu Hengfeng Annex Polytron Technologies Inc
Priority date: 2021-06-11
Filing date: 2021-06-11
Publication date: 2021-09-10

Abstract

The invention provides a method for changing a pulping process of a rod mill, which comprises the following steps: taking out the materials with the specific particle diameter d, wherein the materials account for more than 10 wt% of the total mass of the raw pulp of the rod mill_cpIs fractionated into component A and components B, d_cpIs 80-150 μm, so that the mass ratio between the component A and the component B is (1-9): (9-1); grinding the component A, wherein the average grain diameter of the grinding is less than 20 mu m, and shaping and rubbing the component B to eliminate edges and corners; and mixing the component A and the component B after the treatment in the steps, and adding the mixture into the rest raw pulp of the rod mill. The method for changing the pulping process of the rod mill has the advantages that the component A with strong lubricity and the component B capable of increasing the grading relation among particle sizes are added into the original ore pulp, so that the ore pulp concentration is improved, the operation condition of the whole method is mild, the method is green and environment-friendly, and the cost is low.

Description

Method for changing pulping process of rod mill

Technical Field

The invention relates to the field of mineral processing and ore pulp conveying, in particular to a method for changing a pulping process of a rod mill.

Background

In the mining industry, minerals such as gold tailings, silver tailings, iron ore, phosphate ore, coal and other minerals are often transported from a tunnel to a processing site in close-range pipelines. If vehicle transportation is adopted, the links of manual loading, unloading, transportation and the like are needed, but the general road condition of the mining area of the mine is poor, the vehicle transportation is limited, so that the pipeline transportation is adopted, the difficulty can be reduced, the cost performance is high, and the energy consumption is low.

The traditional process of pipeline transportation is to process mineral substances, grind the mineral substances together with water and a dispersing agent by a rod mill to prepare the mineral pulp with a certain concentration (the particle size of the ground particles is less than 1mm), and then pressurize by a mineral pulp pump and pipeline transport the mineral pulp to users.

The traditional process has certain disadvantages, and the ore pulp concentration is lower. In order to reduce the problem of sedimentation in conveying, the concentration of the prepared ore pulp is lower (in order to reduce kinematic viscosity), and the sedimentation phenomenon (equivalent to hydraulic conveying of minerals) is relieved by increasing the flow speed and pressure, so that the minerals seriously abrade pipelines and equipment due to too high flow speed; secondly, because the concentration of the ore pulp is low, a large amount of water is needed for preparing the ore pulp, and water in a mining area and water in a factory are not balanced mutually, so that a large amount of water resource is wasted; thirdly, because the concentration is low, the energy consumption of subsequent factory processing is very large.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The invention aims to provide a method for changing a pulping process of a rod mill, which improves the pulp concentration by adding a component A with strong lubricity and a component B capable of enlarging the grading relation between particle sizes into original pulp, and is more energy-saving, mild in operation condition, green, environment-friendly and low in cost.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

the invention provides a method for changing a pulping process of a rod mill, which comprises the following steps:

taking out the materials with the specific particle diameter d, wherein the materials account for more than 10 wt% of the total mass of the raw pulp of the rod mill_cpIs fractionated into component A and components B, d_cpIs 80-150 μm, so that the mass ratio between the component A and the component B is (1-9): (9-1);

grinding the component A, wherein the average grain diameter of the grinding is less than 20 mu m, and shaping, rubbing and eliminating edges and corners of the component B;

and mixing the component A and the component B after the treatment in the steps, and adding the mixture into the rest raw pulp of the rod mill.

If high-concentration ore pulp is obtained, two main factors of high-density accumulation and high fluidity of particles need to be solved, high concentration can be realized only by high-density accumulation, and good fluidity can ensure that the high-density accumulation has liquid properties and can be called as 'pulp', otherwise, the high-concentration ore pulp with no fluidity can only be called as 'solid' and can not be called as 'pulp', and if the solid loses the significance of pumping.

Therefore, in order to solve the above problems, the present invention provides a method for changing the pulping process of a rod mill, in which the rod mill is used for grinding, and the grinding efficiency of the rod mill is higher than that of other grinding tools, so the present invention is particularly directed to certain improvement of the pulping process of the rod mill.

Under the same mineral substances, the pulping concentration of the traditional rod mill is the lowest, and the main reason is that certain defects (tight packing cannot be formed) exist in the particle size distribution, the particle size distribution is in normal distribution or 'olive-shaped' distribution (as shown in the attached figure 1), namely, the grading relation is unreasonable due to too many intermediate particles (the reasonable relation is that small particles fill gaps of large particles), tight packing cannot be formed, the gap rate between the particles is large, and the pulp concentration is too low. If there is a means to reduce the intermediate particles or increase the small and large particles (equivalent to reducing the intermediate particles), the final concentration of the pulp can be greatly increased.

The invention extracts a part of primary pulp and processes the part of primary pulp in a grading way to respectively process the component A and the component B, and the main purpose of the invention is to reduce the content of intermediate particles and increase the grading difference, thereby improving the concentration of ore pulp.

The ore pulp particle size distribution after being pulped by the scheme of the invention is shown in figure 2, and the raw material of the raw pulp is extracted, classified and processed into A, B components, and the components are backfilled into the raw pulp, so that the particle size distribution is converted into two obvious peaks from the original single peak, a good grading relation is formed, the stacking density is improved, and the concentration is improved.

In the above-mentioned groups of slurriesIn this regard, mineral component a (which may be considered as "small particles" in the pulp) has two functions: firstly, A plays the lubrication action, and the stronger the lubrication action, the higher the mobility is, the mobility is strong and the concentration-increasing space can be opened. The index of the repose angle is generally adopted for measuring the lubricating property, the smaller the repose angle is, the stronger the lubricating effect is, and the stronger the lubricating effect is, the more the mineral accumulation repose angle is less than 30 degrees, so the repose angle of the component A needs to be limited for improving the lubricating property, and when the repose angle is not controlled within the range required by the scheme of the invention, the fluidity of the whole ore pulp can be influenced. The fluidity of the ore pulp and the size and the grain diameter d of the A_AThe size has a direct relationship. Research shows that when the mineral particles are close to sub-nanometer level, the mineral particles have a certain lubricating effect, and the particle diameters d of different minerals playing a lubricating effect_AIn contrast, the optimum lubricating diameter d is found experimentally_A(diameter d)_AToo large or too small is not beneficial to improving the fluidity) can greatly improve the fluidity of the ore pulp;

in the previous patent, in order to improve the fluidity of the ore pulp, a mode of adding the component A is also involved, but the inventor finds that the ideal high-concentration and high-fluidity effect cannot be achieved only by simply adding the component A through a large amount of practice, so the inventor further improves the method based on the previous patent, a part of the primary pulp is taken out according to a certain proportion and ground, the component A and the component B formed by grinding are backfilled into the primary pulp according to a certain proportion, the inventor finds that the concentration is higher than that of the original mode of adding the component A, and more excellent effect is achieved, and in the whole operation method, the inventor focuses on two parameters: the proportion of the primary pulp taken out and the proportion of the backfilled component A and the component B can ensure that the formed pulp has high concentration and high fluidity at the same time only by controlling the two parameters in a proper range, and the two parameters are obtained by a great deal of practice and exploration of the inventor.

Wherein, the component A and the component B are mixed according to the mass ratio (1-9): (9-1) mixing and then backfilling into the residual raw pulp of the rod mill. The extraction process is equivalent to reducing the intermediate components, the components A and B are equivalent to increasing large particles and small particles, so that the three functions act on the raw stock of the rod mill together, the grading difference is further widened, the embarrassment that the mill has no adjusting means is changed, and the production elasticity is further increased.

Preferably, the total mass percentage of the virgin stock of the rod mill taken out is between 20 and 60 weight percent, and the total mass percentage of the virgin stock of the rod mill taken out can be between 15 weight percent, 25 weight percent, 30 weight percent, 35 weight percent, 40 weight percent, 50 weight percent and more preferably between 30 and 40 weight percent, because if the extraction is less than 20 percent, the A component and the B component which are processed after classification are too small in amount, although the concentration and the fluidity are improved, the improvement is not much compared with the original process; similarly, when the extraction amount is more than 60%, the concentration increasing effect is no longer obvious, and the power consumption and equipment investment are relatively increased due to excessive processing amount, so that the significance is not realized.

Preferably, the mass ratio of component A to component B can be determined by the particle size d_cpThe value of itself is adjusted so that d_cpThe ore pulp with larger gap rate (indicating more large particles) is adjusted according to the stacking gap rate of different ore pulp particles, so that the component A is added for filling, and the ore pulp with small gap rate adopts proper components A and B. Generally controlled in the range of (3-5): (5-7) is most preferable.

D of the invention_cpThe particle size is specified to be between 80 and 150 mu m, the value is determined according to the particle size distribution of the primary pulp, the practice finds that the grading particle size critical value is set in the range, the graded component A and the graded component B are proper in mass ratio, and the backfill has a good effect.

In addition, it should be emphasized that, generally, the amount of the component a is preferably greater than 8-10% of the total pulp amount to obtain a more obvious effect, and the raw pulp extraction ratio is preferably greater than 15%, mainly because 15% of the extracted raw pulp is classified (classified according to a certain ratio), if the extracted raw pulp is classified according to the ratio of 7:3, the finally obtained component a is only marginally greater than 10% (just meeting the requirement of the component a), and in addition, the classification ratio of the component a to the component B is too large (the ratio of the component a is large), the particle size of the obtained raw material particles of the component a is larger (the larger the feeding of the superfine mill is, the power consumption is increased in geometric multiple), the power consumption for preparing the component a is increased invisibly, and the component B is also less; if the grading ratio is too small, the requirement of the component A cannot be met, and the component B is excessive. Therefore, the proportion of the extracted raw stock is properly increased, and more adjustment room is provided. The percentages related to the invention are mass percentages.

Preferably, the particle size of the component a is below 20 μm in order to ensure optimum flowability.

Likewise, in order to ensure a higher bulk density, the sphericity ratio of the component B is greater than 60%.

The invention changes the phenomenon of low pulping concentration of a grinding machine by adding the component A and the component B in the primary pulp and can save more energy consumption for manufacturing the component A at the same time. The effect of reducing energy consumption can be achieved because the traditional process is that the raw stock is directly used as the raw material of the superfine grinding machine for preparing the component A, and the grinding mode is that the raw stock is in the particle size d_cpThe classified fine particles are used as raw materials, and because the granularity of the raw materials is reduced by orders of magnitude, the abrasion is greatly reduced, and more energy is saved.

It should be noted that the mineral slurry is a slurry processed by mineral substances and is a general term for all mineral substances. If the mineral substance needs to be made into slurry, high concentration and high fluidity are necessarily required, so in order to ensure higher concentration and fluidity, the invention optimizes the mass ratio of the two added particle size components and the backfill ratio, and if the parameter ranges are not met, the final high concentration of the ore slurry is influenced.

Compared with the prior art, the invention has the beneficial effects that:

(1) the fluidity is improved by increasing the component A, the contents of coarse particles and fine particles (relatively speaking, intermediate particles are reduced) are improved by increasing the components A and B, the gradation relationship is enlarged, and the ore pulp concentration is obviously improved compared with the primary pulp.

(2) Because the prepared raw material particles of the component A are greatly reduced, the power consumption of the superfine grinding machine is reduced by more than 50 percent, and the system is more energy-saving.

(3) By increasing the A and B components, the adjustable means of traditional mill pulping is increased.

(4) By increasing the total amount of A and B to 100% of the pulp, the pulp concentration is significantly increased compared to conventional mill pulps.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings.

FIG. 1 is a graph of the particle size distribution of a slurry from a conventional rod mill pulping process;

FIG. 2 is a graph of particle size distribution of a slurry using the rod mill pulping process of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

Step one, carrying out an experiment by using an existing ore pulp production line of a certain phosphate ore factory in Shanxi, and specifically carrying out the following operation process:

through laboratory research, the optimal lubricating particle diameter of the phosphate ore is 15 mu m, namely the average particle diameter d of the component A required by preparing ore pulp from the phosphate ore _A15 μm, then the grinding average particle diameter d_AThe experiment was carried out with 15 μm powdered rock phosphate (dry basis) added directly to the existing pulp.

The experimental procedure was as follows:

(1) group ofPreparation of part A: in actual production, according to the scheme, 30 wt% of primary pulp is extracted, and d is designed_cpFractionation was carried out at 120 μm (exactly achieving a: B4: 6, ensuring a to 12 wt% of total pulp), less than d_cpGrinding 120 μm particles to an average particle size d_AThe angle of repose was tested at 26 ° for 15 μm of component a; greater than d_cpThe particles with the diameter of 120 mu m are shaped into the component B, and the sphericity ratio is more than 60 percent and accounts for 18 percent of the total pulp amount.

(2) Average particle diameter d_AThe 15 μm A component (12 wt%) is added into the primary pulp (viscosity 1156mPa.s) and stirred uniformly, the pulp concentration is increased by 3.6% and the viscosity is kept at 1145 mPa.s.

Compared with the traditional preparation method, the high-concentration high-fluidity ore pulp prepared by the embodiment has the advantages that the percentage is increased by 3.6 percent, the stability is higher than 8 hours, hard precipitation is not generated, the apparent viscosity is 1145mPa.s, and the pipeline conveying requirement is met.

And step two, based on the experiment in the step one, when the component A is not added, adding the B component with the spherical rate of more than 60% after shaping into the primary pulp (with the viscosity of 1156mPa.s) in a small amount in batches (5 wt%, 10 wt%, 20 wt%, 30 wt% and 40 wt% of the B component), uniformly stirring, only adding the B component at most 5% under the condition of keeping the original fluidity, increasing the concentration by 0.2%, and then beginning to reduce the fluidity to convert the liquid into the solid.

In this example, the concentration cannot be substantially increased by adding the component B, and the component B cannot be increased more (5 wt% at most). This experiment demonstrates that without good flowability, the bulk density is again insignificant.

And step three, on the basis of the step one and the step two, simultaneously carrying out two measures for testing the superposition effect, and simultaneously adding the prepared component A and the component B (which is equivalent to 30% of extraction and is classified according to the mass ratio of 4:6, so that the A content is 12 wt% and the B content is 18 wt%). The specific operation process is as follows:

the experimental procedure was as follows:

(1) and (4) according to the step one, the concentration of the ore pulp in the production line is improved by 3.6 percentage points.

(2) According to the second step, the concentration of the produced ore pulp cannot be basically improved.

(3) And then, the step one and the step two are carried out simultaneously, the concentration of the final testing ore pulp is improved by 8.1 percent compared with that before implementation, and the viscosity is kept at about 1146mpa.s (similar to that of the primary pulp).

As can be seen from the data of this example, the addition of component A to the original production line improves flowability and concentration; if the component B is added, the ore pulp concentration is improved by more than 4 percent after good fluidity is achieved, the method of simultaneously adding the component B and the component B is implemented simultaneously, the effect is better, and the component B have a superimposed effect. This phenomenon is mainly the extraction of a portion of the original pulp, at d_cpGrading at 120 mu m, and performing superfine grinding on particles smaller than 120 mu m to reach 15 mu m on average, so that 30% of particles between 15 and 120 mu m of the virgin pulp are not present, namely 30% of intermediate particles of the virgin pulp are reduced; meanwhile, the component B (large particles) is added, so that the content of the large particles is increased, the gradation of the large particles and the small particles is enlarged, the bulk density is higher, and the concentration is higher.

Based on example 1, the following groups 1 to 7 were set to compare the parameter changes of example 1, and the specific setting manner and the detection results are shown in the following specific embodiments of groups 1 to 7 and table 1.

Group 1

The specific procedure is identical to that of example 1 above, except that d of component A_A＝30μm。

Group 2

The specific procedure is identical to that described in example 1 above, except that component A has an angle of repose of 40 °.

Group 3-1

The specific operation steps are the same as those of the above example 1, the raw stock ratio is 10%, and the ratio of A to B is 9 to 1 after classification.

Group 3-2

The specific operation steps are the same as those of the above example 1, the raw stock ratio is 10%, and the ratio of A to B is 5 to 5 after classification.

Group 3-3

The specific operation steps are the same as those of the above example 1, the raw stock ratio is 10%, and the ratio of A to B is 1 to 9 after classification.

Group 4-1

The specific operation steps are the same as those of the above example 1, the raw stock ratio is extracted to be 30%, and the ratio of A to B is 9 to 1 after classification.

Group 4-2

The specific operation steps are the same as those of the above example 1, the raw stock ratio is extracted to be 30%, and the ratio of A to B is 5 to 5 after classification.

Group 4-3

The specific operation steps are the same as those of the above example 1, the raw stock ratio is extracted to be 30%, and the ratio of A to B is 1 to 9 after classification.

Group 5-1

The specific operation steps are the same as those of the above example 1, the raw stock ratio is extracted to be 70%, and the ratio of A to B is 1 to 9 after classification.

Group 5-2

The specific operation steps are the same as those of the above example 1, the raw stock ratio is extracted to be 70%, and the A: B is 2:8 after classification.

Group 5-3

The specific operation steps are the same as those of the above example 1, the raw stock ratio is extracted to be 70%, and the ratio of A to B is 5 to 5 after classification.

Group 5-4

The specific operation steps are the same as those of the above example 1, the raw stock ratio is extracted to be 70%, and the ratio of A to B is 9 to 1 after classification.

The results of the experiments were evaluated for each of the above groups, and the results are shown in tables 1 to 4 below.

TABLE 1 results of the experiment

	Original production line	Example 1	Group 1
				Viscosity mpa.s	1156	1146	1160
Concentration wt%	60.2	68.3	62.4
				Change in concentration		+8.1	+2.2

TABLE 2 results of the experiment

	Original production line	Example 1	Group 2
				Viscosity mpa.s	1156	1146	1150
Concentration wt%	60.2	68.3	61.9
				Change in concentration		+8.1	+1.7

TABLE 3 results of the experiment

	Original production line	Example 1	Group 3-1	Group 3-2	Group 3-3
						Viscosity mpa.s	1156	1146	1152	1148	1153
Concentration wt%	60.2	68.3	63.5	62.3	60.5
						Change in concentration		+8.1	+3.3	+2.1	+0.3
Specific power consumption kw/t	28.5	32.6	32.9	29.6	28.9
						The proportion of the component A is wt%	0	12	9	5	1
The proportion of the component B is wt%	0	18	1	5	9
						Extraction ratiowt％	0	30	10	10	10

TABLE 4 results of the experiment

	Original production line	Example 1	Group 4-1	Group 4-2	Group 4-3
						Viscosity mpa.s	1156	1146	1145	1143	1150
Concentration wt%	60.2	68.3	65.5	67.6	60.7
						Change in concentration		+8.1	+5.3	+7.4	+0.5
Specific power consumption kw/t	28.5	32.6	50	32.8	29.2
						The proportion of the component A is wt%	0	12	27	15	3
The proportion of the component B is wt%	0	18	3	15	27
						The extraction ratio is wt%	0	30	30	30	30

TABLE 5 results of the experiment

	Original production line	Example 1	Group 5-1	Group 5-2	Group 5-3	Group 5-4
							Viscosity mpa.s	1156	1146	1160	1157	1146	1151
Concentration wt%	60.2	68.3	66.6	67.8	65.2	62.3
							Change in concentration		+8.1	+6.4	+7.6	+5.0	+2.1
Specific power consumption kw/t	28.5	32.6	29.3	31.5	60.3	80.2
							The proportion of the component A is wt%	0	12	7	14	35	63
The proportion of the component B is wt%	0	18	63	56	35	7
							The extraction ratio is wt%	0	30	70	70	70	70

From the above analysis of experimental data, example 1, compared with each group, can draw the following conclusions:

(1) in Table 1, example 1 is compared with group 1, except that d of component A_A30 μm. The pulp viscosity 1160mpa.s is obtained under the condition of keeping the same fluidity or similar viscosity, the concentration of the added A and B is only improved by 2.2 percent (the component B can only play a role of improving the concentration under the condition of good fluidity), which indicates that the d of the component A_AThe slurry concentration and fluidity are not improved by 30 μm, and it is found that the fluidity improving effect cannot be obtained if the particle size of the component a is not controlled within the set range.

(2) In Table 2, example 1, group 2, is compared, except that component A has an angle of repose of 40. The obtained ore pulp viscosity is 1150mpa.s under the condition of keeping the same fluidity or similar viscosity, the concentration is improved by 1.7 percent points, and the difference is larger than that of the embodiment 1, which shows that if the angle of repose of the component A is larger, the lubricity is not good, and the improvement of the ore pulp concentration is also helped to a certain extent, but if the angle of repose of the component A is within the set range, the effect is more excellent.

(3) In Table 3, example 1 was compared with 3 decimal runs of group 3, with a simultaneous extraction ratio of 10% and different proportions of A and B after fractionation, 9:1, 5:5, 1:9, respectively.

The component A in the group 3-1 is basically ensured to reach 9 percent of the total amount, but the component B is too little, and is only improved by 3.3 percent compared with the primary pulp, and is improved by 4.8 percent compared with the embodiment 1, which shows that the concentration can be basically improved by more than 3 points when the component A with a reasonable proportion is added into the primary pulp, but the component B added in the group 3-1 is too little, so the effect of the embodiment 1 is not achieved.

Although the extraction proportion of the groups 3-2 is the same, the groups are classified according to the ratio of 5:5, the added component A is equal to 5%, the added component B is also 5%, when the component A is insufficient, good fluidity cannot be formed firstly, so the total effect of adding the component B begins to be reduced, the concentration is improved (2.1 percentage points) relative to the original pulp, but the effect is lower than that of the group 3-1, which indicates that the concentration is increased firstly, the amount of the component A must be ensured, and the effect of adding the component B is better.

Groups 3-3 also draw 10% of the ratio, but the grading is according to 1:9, that is, the ratio of component A is only 1%, and the ratio of component B is 9%, and as a result, the concentration is only changed by 0.3 point, the concentration increasing effect is very low, and groups 3-3 further show that when the ratio of component A is less than the reasonable ratio, the effect of adding component B is very small.

The following analysis was performed again from the power consumption in table 3.

It can be seen from the power consumption of several experiments in table 3 that, based on the power consumption of the virgin stock, the more the component a is added, the larger the power consumption is, and the smaller the power consumption is when the component a is added.

From the comparison of the power consumption of example 1 and group 3-1, it can be seen that although the amount of the component A (9%) processed by group 3-1 is less than the amount of the component A (12%) processed by example 1, the power consumption is slightly higher than that of example 1 because the classification ratio of the component A is 90%, and a lot of large particles enter the component A, which results in the increase of the particle size of the feed of the superfine mill, and thus causes the high power consumption. Products with the same yield and fineness are generally processed in the industry, the feeding sizes are different, the power consumption difference is large, and the group 3-1 accords with the industrial phenomenon.

(4) As analyzed from Table 4, example 1 was compared with groups 4-1, 4-2 and 4-3, and the same extraction ratio (30%) as example 1 was obtained, and the ratios of A and B after fractionation were respectively 9:1, 5:5 and 1: 9.

Example 1 and group 4-2 are closer, group 4-2 has a slightly more 3% of component A than example 1 and 3% less of component B, both of which result in similar results, with a slight increase in power consumption, mainly a 3% increase in the amount of grinding component A. This comparison shows that the power consumption is similar for similar particle sizes of the raw materials.

In example 1, compared with group 4-1, component A is greatly increased, component B is greatly decreased, power consumption is also greatly increased, and concentration is decreased. The main reason for analysis is that the quantity of grinding component A is greatly increased, and most of large particles enter component A according to the classification proportion of 9:1, which is equivalent to that the feed particles of component A are processed to be enlarged, and the power consumption is greatly increased due to the superposition of the two factors. Also, although the effect is reduced by one time more than that of example 1, it is also shown that the addition of component A requires "just before" and is rather counterproductive.

Example 1 compared to groups 4-3, component A was severely deficient (only 3%), and the concentration increase was limited by the addition of more component B, further illustrating that component B was added provided that the amount of component A satisfied the high flow requirement.

From the overall analysis in terms of power consumption in Table 4, it is further shown that the greater the amount of processing A, the higher the power consumption, and the greater the feed particle size, the same amount of processing.

(5) As can be seen from groups 5-1, 5-2, 5-3, and 5-4 of Table 5, when the extraction ratio is 70%, the more the processed A component is, the power consumption is greatly increased, mainly for two reasons, the amount of the processed A component is gradually increased, and the other reason is that the larger the A component ratio in classification, the more large particles must enter the A component raw material, that is, the feeding particle size for grinding the A component is greatly increased, and the power consumption is multiplied.

Comparing example 1 with group 5-2, it can be seen that group 5-2 has 14% of the A component greater than 12% of the A component of example 1, but the power consumption is reduced because group 5-2 has a larger extraction ratio than example 1 and more raw materials are classified as the A component, so the particle size of the raw materials of group 5-2 after classification is lower than that of example 1 (the feed particle size is small), and the power consumption is lower than that of example 1, which further illustrates that the particle size of the raw materials of group A directly determines the energy consumption of the project.

As can be seen from several comparative experiments in Table 5, the component A must be added in a proper proportion, the concentration of the component A cannot be increased due to excessive component A, the power consumption is large and cannot be compensated, and the optimal proportion of the component A can be controlled to be between 10 and 20 percent.

(6) Through all the above experimental comparisons, it can be concluded that:

in the whole scheme, firstly, the repose angle of the component A is ensured to be less than 30 degrees, and the component A has strong lubricity so as to improve the fluidity; furthermore, the sphericity of the component B of > 60% is advantageous for flowability. Secondly, the amount of the component A is controlled to be 10-20 percent optimally; and the extraction ratio is controlled to be between 20 and 60 weight percent, which is optimal in terms of effect and energy consumption. In general, the extraction at 30 wt% is sufficient for both efficiency and energy consumption. The percentages referred to in the various embodiments and groups above are percentages by mass.

Example 2

The other steps were identical to those of example 1, except that the ground particle size of component A was 10 μm.

Example 3

The other steps were identical to those of example 1, except that the ground particle size of component A was 20 μm.

Example 4

The other steps were identical to those of example 1, except that the proportion of virgin pulp extracted was 20% by weight.

Example 5

The other steps were identical to those of example 1, except that the proportion of virgin pulp extracted was 60% by weight.

Example 6

The other steps correspond to example 1, except d_cpThe fractionation was carried out at 80 μm.

Example 7

The other steps correspond to example 1, except d_cpThe fractionation was carried out at 150. mu.m.

While particular embodiments of the present invention have been illustrated and described, it would be obvious that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

1. A method for changing a pulping process of a rod mill is characterized by comprising the following steps:

taking out the materials with the specific particle diameter d, wherein the materials account for more than 10 wt% of the total mass of the raw pulp of the rod mill_cpIs divided into component A and groupAre divided into B, d_cpIs 80-150 μm, so that the mass ratio between the component A and the component B is (1-9): (9-1);

2. The method according to claim 1, characterized in that the mass ratio between the component a and the component B is (3-5): (5-7).

3. The process according to claim 1, characterized in that the component a angle of repose is < 30 °.

4. The process according to claim 1, wherein the fraction B is spherical > 60%.

5. The method according to claim 1, wherein the particle size of component a is below 10 μm.

6. The method of claim 1, wherein the total mass of the virgin pulp removed from the rod mill is between 20 wt% and 60 wt%.