RU2788687C1 - Method for preparing the filling mixture of a given consistency (options) - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to the field of mining, namely to hardening stowing mixtures, and can be used in underground mining with backfilling of goaf and contains options for preparing a stowing mixture of a given consistency. A method for preparing a backfill mixture of a given consistency according to any of the options includes dosing the mixture components, mixing them in mixing equipment to obtain a backfill mixture, followed by checking the consistency of the specified mixture. The composition of the filling mixture according to the variants of the method contains the following components in the stated ratios: according to the first - sand, binder and water; on the second - sand, binder, coarse aggregate and water; on the third - sand, binder, plasticizer and water; on the fourth - sand, binder, plasticizer, coarse aggregate and water. Before dosing the components, the applied sand is subdivided into geological differences depending on its physical and mechanical properties. Preliminary development of brand compositions of filling mixtures is carried out in the form of rows of flow charts according to selected characteristic sand samples with a step-by-step consumption of components - binder, water, aggregates within the range of water consumption required to achieve a given consistency. The technological maps indicate the grade of sand, taking into account the geological difference. Before starting the supply of the backfill mixture, a branded technological map is selected that is closest in terms of the consumption of the components of the geological difference of the sand at the entrance to the technology, and the natural moisture content of the aggregates is determined. At the same time, according to the value of the specified moisture, the number of dosed components in the task of dosing equipment is recalculated, and according to the value of natural moisture, the actual composition of the filling mixture is calculated, taking into account all the dosed components. The consistency of the filling mixture is measured, compared with the value of the specified consistency. The control of the filling mixture consistency according to the measurement results is carried out by changing the value of the specified moisture content, namely, by decreasing or increasing the value of the specified moisture content with the possibility of achieving the specified consistency. The natural moisture value is used as a starting point for maintaining a tolerance of the target moisture value relative to the natural moisture value within the water flow range step between adjacent WPSs.

EFFECT: ensuring the preparation of the backfill mixture of a given consistency using aggregates with varying physical and mechanical properties while maintaining the required grade strength and the possibility of preparing the backfill mixture in an in-line production mode.

14 cl, 2 dwg, 4 tbl, 4 ex

Description

The invention relates to the field of mining, namely to hardening stowing mixtures, and can be used in underground mining with goaf backfilling.

A known method of controlling the consistency of the concrete mixture during preparation, including measuring the consistency of the mixture after the first dose of water is supplied, taking into account the maximum moisture content of the aggregates, comparing with the given one and calculating the second dose of water according to the calibration dependence, in order to improve the accuracy of regulation, the value of the second dose obtained from the calibration dependence water is adjusted taking into account the volume of the concrete mixture and the possible maximum error in the dosing of the components downwards, and if the consistency of the concrete mixture deviates from the task after adding the second dose of water, the third dose is determined by the formula m=(m ₂ -m ₀ )/m ₀₂ (SU 1763203, IPC B28C 7/02, published 09/23/1992).

The disadvantage of the known technical solution is the cyclical regulation of the consistency of the mixture with stops of the technological process in order to measure the consistency of the draft of the standard cone (SC), compare it with the value on the calibration dependence of the obtained value of OK and recalculate the actual volume of the concrete mixture, taking into account the value determined by the given formulas. Concrete mixtures are characterized by a low water-cement ratio, which causes a rapid increase in the loss of mobility (thickening of the consistency), and according to the result of measurement with stops in the technological process, distortions occur in the choice of subsequent doses of water in the direction of increasing the calibration dependence, which can have a negative impact on the final strength of concrete after hardening . The technical solution takes into account the influence of only humidity on the consistency of the mixture. In the description of the technical solution, there is no data on the granulometric and material composition of the fillers of the mixture, which affect the water demand of the mixture and, as a result, the consistency of the mixture. This technical solution cannot be applied for the preparation of mixtures in the in-line mode with the required consistency when using natural materials as aggregates with their inherent fluctuations in particle size distribution and material composition.

A known method of preparing a backfill mixture (Montyanova A.N. Formation of backfill massifs in the development of diamond deposits in the permafrost zone. M .: Publishing house "Mining Book", 2005. - 597 p.) from cement, water and aggregate from fine sand, humidity (14 .2 ÷ 32.8%) and fineness (size modulus 0.82 ÷ 1.73; content of dust and clay particles from 3.4 to 30.7%) of which vary over a wide range, providing for preliminary drying of the aggregate before entering the technology preparation of the filling mixture and / or its thawing with hot water in a separate mixer before mixing with the rest of the components in the main mixer.

The disadvantages of this method are: the need to build capital covered warehouses with heat supply for the purpose of preliminary drying with constant movement of sand along the drying site or preheating of water in a special vat and the introduction of additional equipment (mixer) in order to thaw and dissolve the sand before entering the main mixer, which increases the cost of production of filling mixture. At the same time, due to the high variability of sand moisture, taken into account when dosing sand, it is difficult to control the consistency of the filling mixture at the exit, and therefore this method requires advanced adjustment of the compositions and does not provide for the possibility of flexible regulation of the consistency of the mixture by controlling the humidity during the process of its preparation.

The author determined the basic compositions for the production of filling mixtures of a given consistency (flowability according to the Suttard viscometer 16.0-17.5 cm at a water content of 22-23%) and grade (one composition for each grade) based on cement, sand and water. This is due to: the need to ensure stable properties of the sand sent to the technology (the coefficient of variation in sand moisture content and the content of fractions of 0-0.14 mm in it should be no more than 4%); ensuring the water content of the finished filling mixture is not more than 24%. Ensuring the allowable deviations indicated by the author for a significant volume of filler, which is very variable in terms of properties, with in-line technology for preparing backfill mixtures is difficult to achieve or unattainable in most cases. And this is confirmed by the author in the above assumption of the heterogeneity of the formation of the carrier layers with a coefficient of variation of not more than 30%, which indicates a deviation from the required grade: based on the example of the m40 filling mass grade in the direction of not reaching the grade by -1.2 MPa, i.e. up to m28, or exceeding the m40 grade by + 1.2 MPa, i.e. up to m52. The preparation of filling mixtures on aggregates characterized by variable moisture content, density, particle size distribution is characterized by multi-operation, laboriousness and, often, instability of work.

The closest analogue is a hardening filling mixture, including, wt.%:

complex placeholder 55.5-70.0 Portland cement 13.0-19.4 water rest,

while the complex filler includes: substandard very fine natural sand with a particle size modulus of less than 0.7 and increased, more than 15%, the content of clay and dust particles, wt.% 60-95; the rest is the screening of blast-furnace metallurgical slag with a fraction of 0-5 mm (RU 2747753, IPC E21F 15/00, C04B 18/04, C04B 28/04, publ. 13.05.2021).

The disadvantage of the closest analogue is the indication in the description of the use of natural sand in the filling mixture with a vague value of the size modulus and the content of clay and dust-like particles and with the subsequent indication in the approved compositions of unambiguous values for the size modulus and the content of dust-like and clay particles with obtaining absolutely equal spreadability (220 mm) with the indicated fact of a decrease in water consumption from 26.5% to 17%. The fact of reducing water consumption is obtained by calculation from the table 1 given in the description of the invention by subtracting the consumption of cement and aggregate consumption (% per 1 m ³ ) from the sum of all components (100% per 1 m ³ ). The water consumption in kg per 1 m ^{3 of} the mixture for compositions E1-E8 varies from 467 to 330, which follows from the water-cement ratio indicated in the description of the invention: equal to 1.3. According to the costs of the sum "slag + sand + cement" and water for the experimental compositions E1-E8, we derive by dividing the sum of the costs "slag + sand + cement" by the water consumption, the range of the ratio "flow rate "slag + sand + cement": water consumption" = from "2.77:1" to "4.88:1". For the given compositions E1-E8 with an increase in the proportion of coarse aggregate, namely slag, and a decrease in the proportion of fine aggregate, namely sand, in the optimized aggregate, with the indicated fact of reducing cement consumption by 109 kg (from 361 kg to 252 kg) or by 30, 2% and water consumption by 137 kg or 29.4% (from 467 kg to 330 kg), we obtain an increase in the stiffness of the mixture due to a decrease in the amount of fine fractions (for aggregate from 18.29% to 10.89% and for cement by 30 .2% or in total by 37.6%), which together with the water of the mixture act as a carrier medium for the rest of the aggregate. Increasing the stiffness of the mixture worsens its transportable properties. It follows that the achievement of the unambiguous transportable properties indicated by the authors with an unambiguous mixture consistency (flowability 220 mm) with a stated increase in the ratio “consumption“ slag + sand + cement ”: water consumption” = from “2.77: 1” to “4.88 : 1" while maintaining a constant V / C ratio (1.3) with a high degree of probability is impossible.

The second disadvantage of the analogue is the cyclical or batchwise method of preparing the filling mixture. The volume of one portion of the mixer, traditional according to the method of preparation, does not exceed 1.5-3.5 cubic meters. The volume of the backfill pipeline with a horizontal delivery length of up to 3 km is several times greater than the volume of one portion. Batch cooking does not allow for the supply of filling mixture in a continuous mode. The use of storage tanks to accumulate a volume sufficient to fill the filling pipeline and create pressure transportation from the action of the filling mixture column in the vertical part of the pipeline to the goaf complicates the flow diagram and process control.

The third disadvantage lies in the order of supplying the filling mixture components to the mixing equipment, namely, first of all aggregate and cement, and then water after preliminary mixing of the aggregate and cement. This practice is not used in the in-line technology of preparation and supply of backfill mixtures for filling the goaf of mines and mines. Also, the specified order of supply of components increases the energy intensity of the mixing equipment and can cause problems with its wear due to the abrasive effect of the aggregate during mixing without water and transporting the mixture to the inlet to the filling pipeline and through the filling pipeline, since in case of failures in the supply of water and cement, the mixture can acquire a non-transportable consistency.

Preparation of filling mixtures of the required consistency according to the compositions of the filling mixture indicated by the authors, which differ only in the variable ratio in the complex filler of substandard sand and screenings of blast-furnace granulated slag, without taking into account the effect on water consumption, and hence on the consistency of the filling mixture, variable in size modulus (less than 0.7 ) and the content of dust and clay particles (more than 15%) of natural sand in combination with other aggregates (for example, granulated slag) while maintaining the specified strength characteristics is impossible in a continuous mode.

The technical problem solved by the invention is the preparation of a filling mixture of a given consistency in an in-line technological production mode using fillers that vary in physical and mechanical properties (size modulus, granulometric and material composition, moisture content) and ensuring the required grade of the formed filling mass.

The technical result consists in ensuring the preparation of the backfill mixture of a given consistency using fillers with variable physical and mechanical properties while maintaining the required grade strength and the possibility of preparing the backfill mixture in a continuous production mode.

The specified technical result according to any of the options is achieved by the fact that the method of preparing a backfill mixture of a given consistency includes dosing components containing a binder, water, aggregate, including sand, mixing them in mixing equipment to obtain a backfill mixture, followed by checking the consistency of the specified mixture, according to the invention:

1. before dosing the components, the sand used is divided into geological differences depending on its physical and mechanical properties,

2. Preliminary development of brand compositions of filling mixtures is carried out in the form of rows of flow charts based on selected characteristic sand samples with a step-by-step consumption of components (binder, water, aggregates) within the range of water consumption required to achieve a given consistency. The technological maps indicate the grade of sand, taking into account the geological difference.

3. Before starting the filling mixture supply, a branded technological map is selected that is closest in terms of the consumption of the components of the geological difference of the sand at the entrance to the technology, the natural moisture content of the aggregates is determined

4. At the same time, according to the value of the given moisture, the number of dosed components in the task of dosing equipment is recalculated, and according to the value of natural moisture, the actual composition of the filling mixture is calculated, taking into account all the dosed components.

5. Carry out the measurement of the consistency of the stowing mixture, compare with the value of the specified consistency.

6. At the same time, the consistency of the filling mixture is controlled based on the measurement results by changing the value of the specified moisture content, namely, decreasing or increasing the value of the specified moisture content with the possibility of achieving the specified consistency, and the natural moisture value is used as a starting point to maintain the allowable deviation of the specified moisture value relative to the natural moisture value within the step of the range for water consumption between adjacent technological maps.

At the same time, to achieve the technical result according to the first version of the method, the components are used in the following quantitative ratio, wt.%:

- sand 41.7 - 62.9 - astringent 14.4 - 27.8 - water Rest

To achieve the technical result according to the second variant of the method, a large aggregate is included in the composition of the components, and the components are used in the following quantitative ratio, wt.%:

- sand 29.9 - 40.0 - astringent 9.79 - 23.2 - large filler 20.0 - 26.65 - water Rest

To achieve the technical result according to the third version of the method, a plasticizer is included in the composition of the components, and the components are used in the following quantitative ratio, wt.%:

- sand 43.9 - 65.0 - astringent 13.1 - 26.3 - plasticizer 0.46 - 1.14 - water Rest

To achieve the technical result according to the fourth version of the method, the composition of the components includes a coarse filler and a plasticizer, and the components are used in the following quantitative ratio, wt.%:

- sand 31.5 - 41.33 - astringent 8.41 - 21.6 - large filler 21.0 - 27.52 - plasticizer 0.54 - 1.79 - water Rest

In order to simplify further work, sand mining is carried out with preliminary geological testing. For the same reasons, the delivery, storage and storage of sand is carried out according to grades, taking into account geological differences according to quality documents with the indicated physical and mechanical properties: fineness modulus, particle size distribution, content of dust and clay particles.

Sand can be with a fraction size of up to 5 mm.

Coarse aggregate can be with a fraction size of up to 40 mm.

The coarse aggregate may be of natural origin.

In particular, rock crushing waste can be used as a coarse aggregate of natural origin.

Large aggregate may be of technogenic origin.

In particular, slag can be used as a coarse filler of technogenic origin.

In particular, crushed slag waste can be used as a large aggregate of technogenic origin.

Aggregate moisture can be measured using the express water displacement method.

The moisture content of the aggregate is measured by the drying method.

The calculation of the actual composition of the components and the calculation of dosed components can be performed according to the algorithm.

In particular, the algorithm for calculating the actual composition of the components and the calculation of dosed components can be performed using human resources.

In particular, the algorithm for calculating the actual composition of the components and the calculation of dosed components can be performed using human resources and auxiliary programs.

In particular, the algorithm for calculating the actual composition of the components and the calculation of dosed components can be performed by the process control system.

In particular, flow charts with specified costs of components can be in paper or electronic form.

In particular, flow charts with specified costs of components can be installed in the program.

If the measured value of the backfill mixture consistency exceeds or is insufficient to the specified value and the condition of approaching the boundary of the step range in terms of water consumption between adjacent flow charts is met, a transition to another flow chart with a lower or higher water flow can be performed.

After the dosed components enter the mixing equipment, the components of the filling mixture are continuously mixed at a constant rate in the volume provided for by the design of the mixing equipment, with the capacity set and changed, if necessary, during the supply of the mixture output capacity for a time that can be in the range of 33.8 ÷ 157 seconds followed by checking the consistency of the resulting mixture.

In particular, the components can enter the mixing equipment in the following sequence: water, binder, filler.

In particular, when a plasticizer is included in the filling mixture, it is introduced into the water, after which they together enter the mixing equipment.

In particular, when sand and coarse aggregate are included in the aggregate, then sand first begins to flow into the mixing equipment, then coarse aggregate.

The consistency of the mixture can be determined by the viscosity.

In particular, the consistency of the mixture can be determined from the diameter of the mixture on a Suttard viscometer.

In particular, the viscosity of the consistency can be measured by the instrument.

In particular, the viscosity of the consistency can be measured manually by the instrument.

In particular, the viscosity of the consistency can be measured by the instrument in automatic mode.

In particular, the viscosity of the consistency can be measured by a device in automatic mode, implemented directly in the mixer.

In particular, the volume of the mixing equipment may be in the range of 1.5÷3.5 m ³ .

It should be understood that the given equipment parameters and various measurement methods that can be used play an auxiliary role for the implementation of the claimed options for the methods of preparing the backfill mixture and their variations and combinations may vary by specialists in this field of technology, as well as various modifications of these embodiments will be obvious to specialists. in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of application.

The essence of the invention is illustrated by drawings.

Fig.1 - The relationship of varieties and geological differences of sand; figure 2-technological maps compiled in the relationship of varieties and geological differences of sand.

The method for preparing a backfill mixture of a given consistency according to the first variant includes dosing components containing a binder, water, wet aggregate, including sand, mixing them in mixing equipment to obtain a backfill mixture, followed by checking the consistency of said mixture.

The components enter the mixing equipment in the following sequence: water, binder, aggregate. This order of supplying the filling mixture components to the mixing equipment is used for the in-line technology for preparing filling mixtures and makes it possible to reduce the wear of the mixing equipment by mixing the filler in a mixture of binder and water, which reduces the abrasive effect of the filler particles and provides a favorable mode of transportation to the entrance to the backfill pipeline. and through the stowing pipeline, because Such a sequence of supplying components to the dosing equipment in the event of failures in the supply of water and binder makes it possible to eliminate them before switching on the supply of aggregates. For the in-line mode of preparation of filling mixtures, continuous mixers with a side spout are increasingly used. Before the mixture starts to flow out of the mixer, the volume of the mixture from the dosed components is accumulated, which is determined by the design and dimensions of the mixer. The above procedure for supplying components to the mixing equipment reduces its energy consumption and allows obtaining the required transportation parameters to the entrance to the filling pipeline and through the filling pipeline without fear of blockages already at the initial stage of preparing the filling mixture.

In this application, the concepts of coarse aggregate and sand, falling under the category - fine aggregate, are applied. Fine and coarse aggregates are defined according to a source from mining, namely: Mining Encyclopedia. - M.: Soviet Encyclopedia. Edited by E. A. Kozlovsky. 1984-1991. Fine aggregate (sand) can be with a fraction size of up to 5 mm. Coarse aggregate can be with a fraction size of up to 40 mm natural, for example, waste from crushing rocks, or man-made, for example, slag, waste from crushing slag rubble.

Below is a description of how, before dosing the components, the applied sand is divided into geological differences depending on its physical and mechanical properties.

The sand used as a fine aggregate, mined in the backfill sand quarry and used to prepare the backfill mixture, is characterized by significant variability in granulometric and material composition (size modulus from 0.01 to 1.2; content of dust and clay particles from 3 to 15% ), which predetermines a significant variability in water consumption to achieve a given consistency of the filling mixture.

Therefore, sand is subdivided into geological differences depending on its physical and mechanical properties and graded (Table 1) according to the developed technical conditions: the division into grades was carried out according to the fineness modulus and the content of dust and clay particles.

Table 1. Index Sand grade 1 2 below 2 Size modulus 0.8 ÷ 1.2 0.4 ÷ 0.8 less than 0.4 The content of dust and clay particles with a size of -0.05 + 0 mm ≤5% ≤15% ≤12%

The relationship of varieties and geological differences of sand (conditionally indicated by color) is shown in Fig.1.

For sand of each geological difference, separate storage and separate supply to the input of the backfill mixture preparation technology are provided, which makes it possible to understand its physical and mechanical properties (grading, fineness modulus and content of dust and clay particles) according to the quality document indicated in the quality document. The quality document is provided upon receipt of sand for storage.

Taking into account the selected characteristic data on the grading and geological difference of sand, further technological maps are formed with the specified costs of the backfill mixture components with a specified flow rate. This action is necessary to ensure the achievement of the desired consistency and grade properties of the backfill mixture with filler, the granulometric and material composition of which determines a significant range in water consumption and, as a result, a change in binder consumption with a slight allowable deviation in the water-binder ratio.

Before starting the production process for preparing the backfill mixture, from the generated grade series of flow charts, a flow chart is selected that is closest in terms of component consumption, according to the properties known from the quality document, namely: by grade, fineness modulus and content of dust and clay particles, for the incoming geological difference of sand at the entrance to the technology of preparing the filling mixture.

This makes it possible to start preparing the filling mixture with a consistency closest to the desired consistency.

Next, the "natural" moisture content of the filler is measured, which is an important point for further determining the amount of components used in the mixture and creating a backfill mixture of a given consistency.

The value of "natural" moisture performs two functions: virtual, as a starting point, for choosing the value of a given moisture content and physical, in the algorithm for calculating the actual composition of the filling mixture, taking into account all the dosed components.

The method involves the development of a mathematical algorithm that uses two initial moisture content for the aggregate, namely: a given moisture content for dosing calculation and natural moisture content for calculating the actual composition.

Technological maps, an algorithm for calculating the actual composition of the components and calculating the dosed components can be entered into a program or system, for example, an automated process control system (APCS) to ensure the fastest calculation. In this case, the developed mathematical algorithm for calculating and dosing, which provides for the use of two initial moisture content for the filler (set and natural moisture content), is entered into the process control system for the preparation of backfill mixtures, and the technological maps are entered into the database for the process control system for the preparation of backfill mixture.

The value of the measured natural moisture content of the aggregate and the value of the specified moisture content of the aggregate are entered into the process control system in order to launch the built-in mathematical algorithm, while the value of the specified moisture content is assumed to be equal to or less than or greater than the value of natural moisture content.

The process control system recalculates the quantity of dosed components by the value of the specified moisture content, and by the value of natural moisture recalculates the actual composition of the backfill mixture

The automatic process control system for backfill mixture allows you to instantly calculate the amount of wet sand and the amount of water in the task of dosing equipment according to the changes in the values of moisture content and consumption of components when choosing and switching to other flow charts from the grade range, which is very important for the in-line mode of preparing the backfill mixture. Ensuring a continuous technological process for filling the worked-out space in order to achieve the solidity of the carrier layer of the formed backfill mass with a guarantee of the required strength grade. The solidity of the carrier layer and the compliance of its strength with the required grade are the key to the stability and safety of the artificial roof during the downward layered excavation of minerals.

The calculation can be made using human resources, that is, human labor or human using simple software tools, for example, according to the entered formulas that implement a previously developed mathematical calculation algorithm in Microsoft Excel or another program, which will take more time compared to automated calculation , but will not be an obstacle for use in mass production. In addition, this option will be applicable in case of insufficient funds for the purchase of expensive equipment with software for its implementation and will definitely be cheaper than the calculation option using automated systems.

And regardless of the chosen option for the implementation of calculations, in order to achieve a technical result, after selecting a technological map carried out in accordance with the requirements of the technological regulations in accordance with the grade in terms of geological difference and physical and mechanical properties of the aggregate, it will be important to measure the natural moisture content of the aggregate, while using the value of the specified moisture it is necessary to recalculate the number of dosing components, and according to the value of natural moisture, recalculate the actual composition of the filling mixture.

After recalculation, the components are dosed and mixed in mixing equipment to obtain a backfill mixture. At the same time, the technological process of preparing the filling mixture provides for periodic control measurements in order to obtain a product with a given quality at the outlet, therefore, at the outlet of the mixer to the entrance to the filling pipeline, the consistency of the filling mixture is measured, compared with the given one, if the result of measuring the consistency deviates from the given consistency and, according to the methodological instructions for supporting the technological process, they regulate the parameters, namely, they change the value of the specified moisture content up or down from the previously set value with the possibility of achieving the specified consistency of the filling mixture, while the natural moisture value is used as a starting point for maintaining the allowable deviation the value of the set humidity relative to the value of natural moisture within the range step for water between adjacent technological maps. The measurement of the consistency can be carried out, for example, by measuring the diameter of the flowability of the mixture of the resulting consistency on a Suttard viscometer or by other measurement, for example, the viscosity of the mixture with a device, both manually and in automatic mode, implemented on a special separate device or directly in the mixer.

A certain difference in the values of the given and natural humidity corresponds to a certain step range in water consumption between the technological maps of the brand series in the APCS database or physically applicable technological maps.

When developing technological maps in the above example (figure 2), it was found that within each grade of sand a developed range in terms of particle size distribution and material composition, which predetermined more than one water requirement (water consumption) for the backfill mixture within the sand grade. At the same time, for backfill sands present in the quarry in geological differences, sand varieties are developed for mixtures on aggregate, represented only by sand in this example, 8 (eight) flow charts of each brand series with a water flow rate of B ₁ ÷ B ₈ (figure 2), as with and without plasticizer. At the same time, it should be borne in mind that the characteristics of the coarse and fine aggregates used may be different in terms of physical and mechanical properties, which will cause different water demand and the number of technological cards will vary, there may be more or less of them, for example, 7 technological cards per large + fine aggregates (for example, slag + sand) both with and without a plasticizer, and when averaging sand, there can be only 2 technological cards in each grade row. For aggregates with other physical and mechanical properties, the number of technological cards may be different.

*Δ ₁ . Суммарный шаговый диапазон между первой и последней технологическими картами превышает 100 кг. Это создает очень жесткие условия для получения из вариативного по свойствам заполнителя закладочных смесей однозначной консистенции, отвечающей условиям транспортирования по протяженным закладочным трубопроводам сложной конфигурации и укладки в подготовленном выработанном пространстве с заданным углом растекания. Поэтому не исключены ситуации отклонения консистенции (растекаемости) смеси от требуемой нормы в процессе приготовления, в таком случае проводят регулирование количества дозируемых компонентов, изменением значения заданной влажности в сторону уменьшения или увеличения от выставленного ранее значения заданной влажности.The introduction of two moisture content for the filler in the calculation algorithm made it possible to set the range step for water between technological maps so that the number of technological maps decreased several times. The step for water consumption between technological maps is taken equal to Δ ₁ and

* _∆1 . The total stepping range between the first and last routings exceeds 100 kg. This creates very stringent conditions for obtaining filling mixtures of a unique consistency from a filler with variable properties that meets the conditions of transportation along long backfill pipelines of complex configuration and laying in a prepared goaf with a given spreading angle. Therefore, situations of deviation of the consistency (spreadability) of the mixture from the required norm during the preparation process are not excluded, in this case, the amount of dosed components is regulated by changing the value of the set humidity in the direction of decreasing or increasing from the previously set value of the set humidity.

If the measured value of the filling mixture consistency exceeds or is insufficient to the set value and the fact of approaching the step range boundary in terms of water consumption between adjacent flow charts is established, the current flow chart is replaced with another flow chart with a lower or higher water flow rate without stopping the process. The logical algorithm of actions for regulating the consistency is included in the functions of the laboratory for quality control of the filling mixture and the operator of the filling complex.

The calculation of the components of the filling mixture in the selection of compositions is carried out using the known formula of a unit volume: the sum of all volumes of the components of the filling mixture should be equal to 1 m ³ . The volume of each component is determined by dividing the mass of the component by its true density. Indicated in figure 1, the repetition of the grade value is associated with an ambiguous water consumption in the composition of a number of technological maps, i.e. as illustrated in the example shown in figure 2, for sand 1 grade of the same geological difference "yellow", 3 flow charts are applicable with equal increments in increasing water flow; for sand of 2 and <2 grades of the geological difference "red-beige", 5 technological maps are also characteristic with an increase in water consumption; for sand of 1, 2 and <2 grades of geological difference "greenish-gray", 6 technological maps are applicable with a similar trend of increasing water consumption; for sand < 2 grades of the geological difference "white thin" 3 technological maps are characteristic with an equal step of increasing the water flow. Based on the results of the selection of water consumption on characteristic sand samples, in particular sand, taking into account grade and geological difference, the amount of water necessary and sufficient to achieve the desired consistency is determined.

The compositions of the filling mixture, confirming the achievement of the required strength at the age specified for the brand, were obtained as a result of the selection of the component composition in batches with a step-by-step consumption of a binder and pouring sample cubes, followed by their compression test. These compositions are combined into brand series of technological maps and subsequently entered into the database, which can be implemented both on the process control system and in the manual version.

Thus, it has been established that the components in the mixture according to the technological maps entered in the database should be applied in the following quantitative ratio, wt.%:

1. sand 41.7-62.9;

2. binder 14.4-27.8;

3. water - the rest.

This method determines the non-stop flow production and preparation of the filling mixture of the required specified consistency and the required grade when used as a filler of sand with a high variability of physical and mechanical properties.

According to the second variant of the method for preparing the filling mixture of a given consistency, the main operations according to the first variant of the method are applied, the difference lies in the fact that, in addition to sand, coarse aggregate is included in the wet aggregate.

When the aggregate includes sand and coarse aggregates, the mixing equipment first begins to receive sand and then coarse aggregate. This order is due to the order in which the dosing equipment is switched on in order to enter the aggregate into the mixing equipment in the order of priority of increasing its fineness, i.e. first sand and then coarse aggregate. This procedure avoids problems with the wear of the mixing equipment, transportation to the entrance to the backfill pipeline and through the backfill pipeline, and reduces the energy intensity of the mixing equipment. Fine particles of fine aggregate (sand), together with binder particles and water, envelop smaller and larger particles during mixing and create a carrier medium for their transportation through the pipeline and when spreading in the goaf.

The difference in the use of coarse filler is the reduction in water consumption in the compositions and, as a result, the decrease in binder consumption for equivalent branded backfill mixtures due to a decrease in the total area of the filler particles and a decrease in the shrinkage of the backfill mass. Reduced shrinkage reduces the time to fill the worked-out space and increases the efficiency of backfilling. In addition, the introduction of coarse aggregate into the aggregate improves the structural skeleton of the hardening backfilling array, which increases the stability and safety of the formed backfilling array.

The advantage of using coarse aggregate as part of the aggregate is to reduce the cost of production of backfill mixtures.

In the case of using a coarse aggregate, the components in the mixture should be used in the following quantitative ratio, wt.%:

1. sand 29.9-40.0;

2. binder 9.79-23.2;

3. coarse aggregate 20.0-26.65;

4. water - the rest.

This method causes non-stop flow production and preparation of the backfill mixture of the required specified consistency and required grade with reduced consumption of binder and water, shrinkage of the backfill mass and improved structural skeleton of the backfill mass when used as part of the filler together with sand with a high variability of physical and mechanical properties and coarse sand. placeholder.

According to the third variant of the method for preparing the filling mixture of a given consistency, the main operations are applied according to the first variant of the method, the difference lies in the fact that a plasticizer is included in the composition of the mixture components.

The plasticizer is used to increase the residence time of aggregate and binder particles in a mobile dispersed state with simultaneous water reduction of part of the water, which makes it possible to reduce water consumption and binder consumption and, as a result, reduce the cost of 1 m ^{3 of} filling mixture while maintaining the required grade. At the same time, the introduced amount of the plasticizer ensures the equivalence of the given consistency of the filling mixture with the plasticizer to the given value of the consistency of the filling mixtures that do not have a plasticizer in their composition.

The plasticizer is introduced into the water before it is fed into the mixing equipment, which makes it possible to achieve its uniform distribution throughout the volume of the binder and aggregates during mixing in the mixing equipment and to ensure the achievement of the desired consistency at the outlet of the mixer.

The advantage of using a plasticizer in the mixture is to improve the transportable properties of the filling mixture by increasing its viability (the ability to maintain a given consistency for a longer period of time due to the presence of binder and aggregate particles, in this variant of sand, in a mobile dispersed state) and reducing the shrinkage of the filling mixture by increasing the consumption of filler in its composition.

In the case of using a plasticizer in the filling mixture, the components should be used in the following quantitative ratio, wt.%:

1. sand 43.9-65.0;

2. binder 13.1-26.3;

3. plasticizer 0.46-1.14;

4. water - the rest.

This method causes non-stop flow production and preparation of backfill mixture of a given consistency with an increased viability cycle, reduced cost of 1 m ³ backfill mixture and reduced time for backfilling workings (shrinkage is reduced) while ensuring the required grade when used as part of sand filler components with high variability physical and mechanical properties and plasticizer.

According to the fourth variant of the method for preparing the filling mixture of a given consistency, the main operations of the first variant of the method are applied, the difference lies in the fact that the composition of the mixture components includes a plasticizer introduced into the water before it is fed into the mixing equipment, and in addition to the sand, coarse aggregate is included in the wet aggregate.

The advantage of using a plasticizer and coarse aggregate in a mixture is that a reduction in water consumption and a binder consumption of branded backfill mixtures is achieved by combining the effects of a coarse aggregate: by reducing the total area of aggregate particles, and from a plasticizer: water reduction due to a change in the nature of the interaction of binder particles with water. At the same time, the plasticizing effect increases the viability of the mixture: the residence time of the aggregate particles, which can include both sand and coarse aggregate, and the binder in a mobile dispersed state while maintaining a given consistency. As a result, a total reduction in the shrinkage of the backfill mass and a reduction in the time to fill the mined-out space were achieved. In addition, when a plasticizer is included in the backfill mixture, the amount of coarse filler introduced into the aggregate increases, which increases the effect of improving the structural skeleton of the hardening backfill mass, and, as a result, increases the stability and safety of the formed backfill mass.

In the case of the use of a plasticizer and coarse aggregate, in addition to sand, binder and water, the components in the mixture should be used in the following quantitative ratio, wt.%:

1. sand 31.5-41.33;

2. binder 8.41-21.6;

3. coarse filler 21.0-27.52;

4. plasticizer 0.54-1.79;

5. water - the rest.

This method causes non-stop flow production and preparation of backfill mixture of a given consistency with an increased viability cycle, with an additional reduction in the cost of 1 m ^{3 of} backfill mixture and a reduction in the time for backfilling workings (shrinkage is reduced) and ensuring the required grade when used as part of a sand filler with high variability physical and mechanical properties and coarse aggregates, such as slag and plasticizer.

The use of the claimed method of preparing a backfill mixture of a given consistency according to any of the described variants of the methods provides flexible regulation of water consumption and aggregate consumption with recalculation of the mixture components and leveling the effect of significant variability of fine aggregate (sand) in terms of particle size distribution and material composition (size modulus from 0.01 to 1.2; the content of dust and clay particles from 3 to 15%) on the consistency of the finished mixture with control measurements of the consistency of the mixture without stopping the process equipment, which leads to a continuous flow production technology and obtaining a filling mixture of a given consistency at the outlet.

от указанных объемов мерных цилиндров, а именно для воды - 500 мл или 1000 мл, соответственно, и влажного заполнителя - 500 г или 1000 г, соответственно. Мерный цилиндр устанавливают на ровной поверхности. Аналитическую пробу высыпают в мерный цилиндр с водой. С внутренних стенок мерного цилиндра частицы заполнителя смывают водой находящейся в цилиндре, для этого цилиндр осторожно наклоняют из стороны в сторону. Дают успокоиться содержимому цилиндра в течение 2-5 минут. При скоплении пузырьков воздуха их осторожно удаляют стеклянной палочкой. Фиксируют образованный объем в мерном цилиндре по уровню воды. Результат записывают. Образованный объем в мерном цилиндре есть сумма объемов сухого заполнителя и объема воды. Вычисляют влажность заполнителя в % по формуле:Sand moisture measurement can be carried out, for example, by the rapid water displacement method or by the drying method. The express method was developed by the author of the invention on the basis of known methods for determining the density of bulk materials by the volume of water displacement. The author's method is given as an example of a measurement, and therefore does not exclude the use of another method. The true density of the filler is taken as the average between the density of the filler by displacement in water of the dry standard filler and the true density determined by the pycnometric method. The true density of the aggregate is included in the calculation to determine the volume occupied by the dry aggregate in the measuring cylinder. We proceed from the condition of constancy of the volume of water to which the same mass of wet aggregate is added, while the mass of dry aggregate will be variable. When deriving the formula for calculating the moisture content of the filler, the change in the volume of water is taken into account due to the introduction of an additional volume of water into the initial volume of water, which makes up the moisture content of the filler. A measuring cylinder with a volume of 1000 ml to 2000 ml is determined for use. Set the requirement for the number of initial components equal to

from the indicated volumes of measuring cylinders, namely for water - 500 ml or 1000 ml, respectively, and wet aggregate - 500 g or 1000 g, respectively. The measuring cylinder is placed on a level surface. The analytical sample is poured into a measuring cylinder with water. From the inner walls of the measuring cylinder, the filler particles are washed off with water in the cylinder; for this, the cylinder is carefully tilted from side to side. The contents of the cylinder are allowed to settle for 2-5 minutes. If air bubbles accumulate, they are carefully removed with a glass rod. The formed volume is fixed in a measuring cylinder according to the water level. The result is recorded. The generated volume in the measuring cylinder is the sum of the volumes of dry aggregate and the volume of water. Calculate the moisture content of the aggregate in% according to the formula:

where: V in + zap. - formed volume in the cylinder (the sum of the volumes of dry aggregate and the volume of water), ml;

V v1 - the initial volume of water in the cylinder (500 ml);

Υ app. - dry aggregate density, taken as the average between the density of displacement in water of the standard and the true density, determined by the pycnometric method, g/cm ³ ;

M vl.zap. - weight of the sample of wet aggregate, g.

When deriving formula (1), we used the formula for determining the dry mass from the known wet mass obtained from the formulaW=(m _ow -m _dry )/m _dry (GOST 8735).

Drying method - method from GOST 8735. Humidity is determined by comparing the mass of the sample in the wet state and after drying. Drying is carried out in an oven to constant weight at a temperature of 100 ± 5 °C. The mass of the original sample (in the wet state) is determined by the GOST requirement and is equal to 1000 g. The moisture content of the aggregate sample by weight in percent is calculated by the formula:

where W is the moisture content of the filler, %; m _in - the mass of the sample before drying, g; m _s is the mass of the sample after drying, g.

When programming an automated process control system (APCS) for the production of backfill mixture, an algorithm for calculating the amount of dosed filler and water is implemented, which is pre-entered into the program, and flow charts with specified component costs are installed in the program.

The mathematical algorithm introduced into the process control system allows, due to instant calculations, to change the task for dosing wet aggregates and water consumption when the value of the specified moisture content changes, which provides a high speed control of the mixture consistency in order to achieve the desired consistency, which is very important for flow technology.

When performing a mathematical algorithm for calculating the amount of dosed aggregate and water using human resources, the duration of the calculation in time increases somewhat, but it can also be implemented.

The formula for calculating the amount of wet aggregate takes into account the amount of dry aggregate from the consumption indicated in the technological map located in the APCS database. The formula is derived from the well-known formula for determining the moisture content of bulk materials (2) and has the form:

where: Mvl. - mass of wet material (in this case aggregate);

Msuh. - mass of dry material (in this case aggregate);

Wref. - specified moisture content of the filler, %.

The task for dosing aggregates is calculated by the system, taking into account the productivity entered into the database (before the start of supply and during supply) by the output of the filling mixture according to the formula:

where: Qzad.zap. - the task for dosing the filler;

Mvl. - mass of wet aggregate;

Qset.c.cm - the specified performance for the output of the backfill mixture.

The system calculates the water consumption target according to the entered formula minus water according to the entered value of the set humidity:

where: Qzad.vody - task for dosing water;

MV because - mass of water according to the technological map;

Mzap.because - mass of filler according to the technological map.

The amount of dry aggregate from the amount of wet aggregate actually dosed, taking into account the value of the specified moisture content and fixed by the system, is determined automatically from the algorithm according to the formula:

where: Wzar.natural. - measured and entered in the process control system the value of the natural moisture content of the filler.

The amount of water included in the filling mixture from the actually dosed, taking into account the value of the specified moisture content, follows from the formula:

After the dosed components enter the mixing equipment, the filling mixture components are continuously mixed at a constant speed in the volume provided for by the design ^of the mixing equipment, which can be, for example, 1.5÷3.5 m by the output of the mixture for a time that can be in the range of 33.8 ÷ 157 seconds, followed by checking the spreadability of the resulting mixture.

An example of the implementation of a method for preparing a filling mixture of a given consistency containing a binder, water, wet aggregate, including sand, which is preliminarily subdivided into geological differences depending on its physical and mechanical properties with grade assignment, according to the developed specifications, according to the first option:

Sand was used to prepare the filling mixture in the flow mode, and sand of 4 geological differences with physical and mechanical properties (Table 2) was delivered to the warehouse of the surface backfilling complex (SSC) from the backfilling sands quarry (Table 2), according to those specified in the quality document. Separate storage of sand by grades and type of geological difference is provided.

Table 2. Geological sand difference Size module Grading:
partial residue (%) on sieve with mesh size (mm) Sand grade Dav., cm Sud.p. cm ² /g 1.25 0.63 0.315 0.16 0.05 0 Yellow 1.08 0 1.4 24.2 55.3 13.7 5.4 1 0.0268 862 Greenish gray 0.46 0 5.4 2.7 24.6 52.3 15.0 2 0.0173 1335 Red-beige 0.66 0 0 0.4 64.9 27.7 7.0 2 0.0178 1299 White thin 0.046 0 0 0.2 4.2 84.8 10.8 below 2 0.0094 2461 After averaging 4 geological differences of sand, taking into account the share of occurrence in the quarry: average sand 0.47 0 1.51 6.12 30.21 51.67 10.50 2 0.0164 1411

The filler used in the preparation of filling mixtures is not fractionated, but has a granulometric and material composition determined by natural (geological) conditions and technological parameters of extraction and preparation, which leads to obtaining, with the same or close modulus of fineness of filler, differences in the average diameter (Dav.) conditionally average its particles and specific surface area (Ssp.p.). So, for example, according to table 2, the sand of the geological difference "greenish-gray" has a size modulus = 0.46, which differs from the size modulus of the average sand (size modulus = 0.47) by -0.01 values, while the distribution the number of particles by size in the granulometric composition is different, which causes a difference in the average diameter (Dav.) of a conditionally average particle and the specific surface area (Ssp.p.) between these sands. This difference predetermines the difference in water consumption with the redistribution of the remaining components in 1 m ^{3 of} the filling mixture within the framework of an unambiguous brand series to achieve a given consistency.

An application was received from an underground mine at 2 (two) addresses for the preparation and supply of backfill mixture for filling mine workings, namely, at the first address, a backfill mixture of brand m100 was ordered for a carrier layer with a volume of 900 m ^{3 of} a one-time supply, and at the second address - a backfill mixture brand m40 on the topping layer with a one-time supply of at least 240 m ³ with a capacity for preparing the filling mixture of at least 100 m ³ / h. With the duration of the working shift of the PZK equal to 12 hours, the application of the underground mine will be executed both in terms of volume in a non-stop mode for each grade, in accordance with the sequence established by the underground mine, and in terms of quality using the method of preparing a filling mixture of a given consistency with a guarantee of the required grade.

According to the requirements of the technological regulations for the conduct of the production process for the preparation of the filling mixture, the technological map is selected in accordance with the grade according to the geological difference and the physical and mechanical properties of the aggregate available in the PZK warehouse. To ensure faster achievement of the required technological parameters by the stowing mixture in the example, the technological maps and calculation methods are entered in the process control system, but this can also be done by human labor without the use of software.

When choosing one of four geological differences for supplying sand to the technology (Table 2): either yellow, or greenish-gray, or red-beige or white fine sand, the technological maps that are closest in terms of water consumption are selected from the grade range of technological maps entered into the process control system a map with the following quantitative ratio of components, as indicated in Table 3 for clarification:

Table 3 Quantitative ratio of components according to the brand range, % The closest value of the quantitative ratio of components (%) for the properties of sand (Table 2): Yellow Greenish gray Red-beige White thin 1. Sand 41.7 - 62.9 brand of filling mixture: m40 60.8 53.3 58.5 50.4 brand of filling mixture: m100 53.5 46.3 51.2 43.3 2. Astringent 14.4 - 27.8 brand of filling mixture: m40 15.2 18.1 16.0 19.5 brand of filling mixture: m100 22.7 25.5 23.6 27.0 3. Water - the rest rest rest rest rest

And provided that averaged sand, composed of imported four geological differences (Table 2), is supplied to the input of the technology, for the preparation of the indicated grades of backfill mixture, other closest technological maps from the grade range with components in the following quantitative ratio, wt.% will be selected:

Generalized for brand series Value for selected routings for m40 for m100 1. sand 41.7 - 62.9 56.0 48.8 2. binder 14.4 - 27.8 17.0 24.5 3. water - the rest rest rest

The laboratory of the backfilling complex determines the natural moisture content of the aggregates by the express method using the selected sand sample and duplicates its determination by the drying method. In this case, the result by the drying method will be known no earlier than in 5-6 hours, and the determination of moisture content by the express method lasts no more than 2 minutes. Therefore, the value of natural moisture determined by the express method is entered in the process control system.

If the backfill mixture has not yet been prepared on the imported sand in the previous shift, then the value of the specified moisture content for entering into the process control system is taken equal to the value of the natural moisture content. If in the previous shift sand with the properties indicated in Table 2 was already used in the preparation of the filling mixture, then the value of the specified moisture content is taken:

- equal to the value of the specified humidity used in the previous shift, provided that the result of determining the natural humidity by the express method is equal to the value of the natural humidity of the previous shift;

- or change the value of the set humidity by the difference between the value of the natural and set humidity of the previous shift, provided that the result of determining the natural humidity by the express method does not match the value of the natural humidity of the previous shift.

The laboratory reports the values of the set and natural humidity and the number of the flow chart components selected closest in terms of consumption to the PZK operator.

According to the values of the specified sand moisture content entered by the PZK operator and the selected technological map, the process control system performs an instant recalculation of the number of dosed components that begin to enter the mixing equipment in the following sequence: water, binder, then sand with a small time interval, the duration of which determines the time to start the dispensers and the specified distance according to the technological scheme from the dosing equipment to the inlet to the mixer. The mixer performs continuous mixing of the incoming components in a constantly replenished volume (1.5 m ³ ), created by the constructive arrangement of the lower level of the hole for the side pouring of the mixture, at a constant speed at a given capacity (100 m ³ /h). Not less than 54 seconds later, the pouring of the filling mixture from the mixer into the transportation system, which is open for sampling, to the entrance to the filling pipeline, begins. At the same time, the process control system recalculates the actual composition of the backfill mixture based on the value of natural moisture coming from the output of the sand dispenser, binder dispenser and water dispenser, taking into account the calculation frequency specified by the conditions in the introduced algorithm.

The laboratory performs sampling of the filling mixture at the outlet of the mixer and determines its consistency by flowability on a Suttard viscometer. For backfilling mixture on sand filler, the regulations for backfilling operations set the optimal working consistency value (set consistency) when spreadability = 22.0 cm, with an allowable range of 21.0 to 22.5 cm. If the value of the result of measuring the consistency differs from the specified consistency, then the laboratory in contact with the PZK operator (the operator enters data on the moisture values received from the laboratory) changes the value of the specified moisture content in the process control system upwards from the previously set value if the spreadability exceeds 22.0 cm, or - downwards if flow measurement is less than 22.0 cm to achieve the desired consistency.

*Δ₁) по расходу воды между соседними технологическими картами, что показано в таблице 4.In doing so, the laboratory uses the natural moisture value of the aggregate as a starting point for keeping the change in the setpoint moisture value within the allowable deviation from the natural moisture value. The range of the difference between the values of the set and natural humidity is commensurate with the step (Δ ₁ and

*Δ ₁ ) by water flow between adjacent flow charts, as shown in Table 4.

Table 4 Difference between set and natural humidity, % Water consumption step between adjacent tehn. cards, kg (l) Filling mix brand from before If the result of measuring the consistency exceeds the specified one, it is necessary to reduce the spreadability (increase the density of the mixture) +1.9 +2.3 _∆1 m40 +1.1 +1.3

*Δ₁

* _∆1 +2.0 +2.6 _∆1 m100 +1.3 +1.5

* _∆1 If the result of measuring the consistency is insufficient above the given one, it is necessary to increase the spreadability (reduce the density of the mixture) -1.8 -2.2 _∆1 m40 -1.2 -1.4

* _∆1 -2.0 -2.5 _∆1 m100 -1.3 -1.5

* _∆1

If the range for the allowable difference between the values of the specified and natural moisture content has been exhausted and the specified value of the consistency has not been obtained, then the laboratory informs the PZK operator of the number of the selected adjacent technological map to be entered into the process control system. When choosing the value of the specified moisture content and making a decision on the transition to another flow chart from the brand range, the laboratory uses the equality “± 1% of the specified moisture value = 0.5 cm ± 0.1 consistency along the Suttard diameter” (these values are given as an example to determine consistency by flowability according to Suttard; with the use of other means there will be other guidelines), established during the preliminary selection of water consumption in the development of branded series of technological maps on a filler with variable physical and mechanical properties. Therefore, the process of regulating the consistency of the mixture to achieve the desired consistency does not take much time and makes it possible to prepare the filling mixture in a streaming mode with the required quality parameters. The control of the brand parameters of the backfill mixture is carried out by testing sample cubes for compression in a timely manner in accordance with the requirements of regulatory documents. Preliminarily developed and entered into the database series of branded flow charts are the guarantor of achieving the required branded strength with a non-stop in-line method of preparing the backfill mixture on a filler with varying physical and mechanical properties.

According to the second embodiment of the method for preparing a backfill mixture of a given consistency, sand is used and granulated blast-furnace slag is used as a coarse filler.

On the surface backfill complex No. 2 (PZK No. 2) sand was delivered from the backfill sand quarry below the 2nd grade according to the geological difference “white thin” and blast furnace granulated slag (DGSh) with physical and mechanical properties:

Aggregate Size modulus Particle size distribution: partial residue (%) on a sieve with a mesh size (mm) 2.5 1.25 0.63 0.315 0.16 0.05 0 Fine white sand below grade 2 0.01-0.046 0 0 0 0.1-0.2 0.7-4.2 91.7-84.8 7.5-10.8 DGSh 2.54-2.70 0.45-1.73 13.55-20.64 38.18-39.27 27.09-30.55 6.73-7.91 2.73-4.18 1.27-2.09

An application was received from an underground mine for the preparation of 2400 m ³ of the m40 stowing mixture for a one-time supply to the carrier layer in the prepared goaf with a cooking capacity of 120 to 130 m ³ /h.

According to the second example, technological maps are entered in the process control system and the recalculation of components and composition is implemented in it, in practice, these operations can be performed manually. From the flow charts generated and entered into the APCS database on the aggregate of sand and slag (slag is a coarse aggregate in relation to sand) of the M40 grade series, the flow chart is selected that is closest in terms of component consumption for white fine sand and slag, focusing on the range of particle size distribution of white fine sand below grade 2, according to the quality document, and the range of slag particle size distribution, determined from slag samples by the PZK No. 2 laboratory.

The laboratory measures the natural moisture content of sand and slag, reports to the operator the values of the natural moisture content of sand and slag and the selected values of the specified moisture content of sand and slag for their entry into the process control system.

The process control system recalculates the amount of dosing components, in this case, sand and slag, according to the entered value of the specified moisture content and the selected technological map, and recalculates the actual composition of the backfill mixture according to the value of the natural moisture content of sand and slag,

at the same time, the components in the filling mixture are used in the following quantitative ratio, wt.%:

Generalized for brand series Value for selected routings 1. sand 29.9 - 40.0 29.9 - 30.7 2. binder 9.79 - 23.2 22.7 - 23.2 3. coarse aggregate 20.0 - 26.65 20.0 - 20.4 4. water - the rest rest

*Δ₁, а допустимое отклонение по разнице между значениями заданной и естественной влажностей не превышает+1,1%, но не ниже -1,2%, при превышении растекаемости по результату замера ее необходимо уменьшить, а при недостаточности растекаемости ее необходимо увеличить для достижения имеющейся консистенции значению заданной. Действия по переходу на соседнюю технологическую карту с большим или меньшим расходом воды при использовании в качестве заполнителя песка и шлака те же, что и в примере по первому варианту способа.Next, the PZK operator No. 2 starts feeding and, according to the data entered in the process control system, dosing of the components that enter the mixing equipment in the following sequence: water, binder, sand and then coarse aggregate - slag, their mixing in mixing equipment with a constantly replenished volume (3, 5 m ³ ), created by the constructive arrangement of the lower level of the hole for the side pouring of the mixture, at a constant speed at a given capacity. When operating at a capacity of 120 m ³ /h, after 105 seconds, the backfill mixture is poured from the mixer into the transportation system, which is open for sampling, before entering the backfill pipeline. The laboratory performs sampling of the filling mixture and determines its consistency by spreadability on the Suttard viscometer. For stowing mixture on aggregate made of sand and coarse aggregate, in particular slag, the regulations for stowing work set the optimal working consistency value (given consistency) when spreadability = 21.0 cm, with an allowable range of 20.0 to 21.5 cm. If the value of the result of measuring the spreadability shows that the consistency differs from the specified consistency, then the same actions are performed as in the example according to the first variant of the method, to achieve the desired consistency with one difference, that all these actions are carried out with a large filler - with slag. At the same time, the value of the natural moisture content of sand and slag is used as a starting point for the allowable deviation of the value of the specified moisture content of sand and slag relative to the value of the natural moisture content of sand and slag within the step of the range of water flow between adjacent flow charts. The step of the range for water consumption between the selected technological maps is

*Δ ₁ , and the permissible deviation in the difference between the values of the given and natural humidity does not exceed + 1.1%, but not lower than -1.2%, if the spreadability is exceeded by the measurement result, it must be reduced, and if the spreadability is insufficient, it must be increased to achievement of the existing consistency to the value given. The steps for switching to an adjacent technological map with a higher or lower water consumption when using sand and slag as a filler are the same as in the example according to the first variant of the method.

The preparation of the filling mixture of a given consistency according to the second variant of the method with a wet aggregate of sand and slag resulted in a decrease in the consumption of water and binder, shrinkage of the filling mixture in the mined-out space, and an improvement in the structure of the formed filling mass by replacing part of the very fine sand with larger slag. Through the system of vertical, horizontal main and local stowing pipelines, the stowing mixture with a given consistency, determined by the spreadability equal to 21.0 cm, enters the worked-out space limited by the jumper and fills it in non-stop mode in accordance with the volume specified in the application.

An example of implementation according to the third option can be an example according to the first method of preparing a backfill mixture of a given consistency, including water, binder, sand, the components of which include a plasticizer. The sequence of actions for the implementation of the method is preserved, the difference will be in the choice of technological cards from the branded series of technological cards, the components of which include a plasticizer. The plasticizer is dosed before entering the mixer into the water, after which it, together with the water, enters the mixing equipment. In this option, the backfill mixture components will be used in the following quantitative ratio (provided that averaged sand, composed of imported four geological differences with different physical and mechanical properties according to Table 2, is supplied to the input of the backfill mixture preparation technology):

Generalized for brand series Value for selected routings for m40 for m100 1. sand 43.9 - 65.0 58.2 50.9 2. binder 13.1 - 26.3 15.6 23.1 3. plasticizer 0.46 - 1.14 1.0 0.51 4. water - the rest rest rest

The preparation of the backfill mixture of a given consistency according to the third variant of the method with wet aggregate from sand with the introduction of a plasticizer into the composition of the mixture components gave an increase in the viability of the backfill mixture: the time spent by the filler particles (sand and slag) and binder in a mobile dispersed state while maintaining the specified consistency of the backfill mixture, reducing water consumption: water reduction by changing the nature of the interaction of binder particles with water and binder consumption, shrinkage of the filling mixture in the goaf. Through the system of vertical, horizontal main and local stowing pipelines, the stowing mixture with a given consistency, determined by the spreadability equal to 22.0 cm, with an allowable range of 21.0 to 22.5 cm, enters the worked-out space limited by the jumper and fills it in non-stop mode in in accordance with the volume specified in the application.

As an implementation example according to the fourth variant, an implementation example according to the second variant of the method for preparing a filling mixture of a given consistency, including water, binder, aggregate, including sand and coarse aggregates, with the difference that a plasticizer is included in the composition of the components, is used. The sequence of actions for the implementation of the method is preserved, the difference will be in the choice of flow sheets, which will be carried out from a branded series of flow sheets with sand filler and coarse aggregates, the components of which include a plasticizer. The plasticizer is dosed before entering the mixer into the water, after which it, together with water, enters the mixing equipment, and the components of the filling mixture will be used in the following quantitative ratio:

Generalized for brand series Value for selected routings 1. sand 31.5 - 41.33 35.8 - 36.5 2. binder 8.41 - 21.6 13.6 - 14.0 3. coarse aggregate 21.0 - 27.52 23.9 - 24.9 4. plasticizer 0.54 - 1.79 1.12 - 1.14 5. water - the rest rest

The preparation of a filling mixture of a given consistency according to the fourth variant of the method with a wet aggregate of sand and coarse aggregates with the introduction of a plasticizer into the composition of the mixture components reduces the consumption of water and the consumption of a binder of branded filling mixtures with the combination of effects from a coarse aggregate (slag): by reducing the total area of particles filler, and from a plasticizer: water reduction due to a change in the nature of the interaction of binder particles with water. At the same time, the plasticizing effect increases the viability of the mixture: the time spent by particles of aggregates (sand and slag) and binder in a mobile dispersed state while maintaining a given consistency. As a result, a total reduction in the shrinkage of the backfill mass and a reduction in the time to fill the mined-out space were achieved. In addition, when a plasticizer is included in the backfill mixture, the amount of coarse filler (slag) introduced into the aggregate increases, which increases the effect of improving the structural skeleton of the hardening backfill mass, and, as a result, increases the stability and safety of the formed backfill mass. Through the system of vertical, horizontal main and local stowing pipelines, the stowing mixture with a given consistency, determined by the spreadability equal to 21.0 cm, with an allowable range of 20.0 to 21.5 cm, enters the worked-out space limited by the jumper and fills it in non-stop mode in in accordance with the volume specified in the application.

Thus, the claimed invention for each of the four variants of the method ensures the preparation of a backfill mixture of a given consistency using wet aggregates with varying physical and mechanical properties, while maintaining the required grade strength and the possibility of preparing a backfill mixture in an in-line production mode.

Claims (56)

1. A method for preparing a backfill mixture of a given consistency, including dosing components containing a binder, water, wet aggregate, including sand, mixing them in mixing equipment to obtain a backfill mixture, followed by checking the consistency of the specified mixture, characterized in that before dosing the components, the sand used is divided into geological differences depending on its physical and mechanical properties, then flow charts are formed with the given costs of the components of the filling mixture with a set step for the flow, choose a flow chart that is closest in terms of the consumption of the components of the geological difference of sand at the entrance to the technology for preparing the filling mixture, measure the natural moisture content of the aggregate, at the same time, according to the value of the specified moisture, the number of dosed components is recalculated, and according to the value of natural moisture, the actual composition of the filling mixture is recalculated, after mixing, the consistency of the backfill mixture is measured, compared with the value of the specified consistency, if the result of the measurement of the consistency deviates from the specified consistency, the value of the specified moisture content is changed up or down from the previously set value with the possibility of achieving the specified consistency of the backfill mixture, while the value of natural moisture is used as a starting point for the allowable deviation of the value of the specified moisture relative to the value of natural moisture within the step of the range for water flow between adjacent flow charts, while the components are used in the following proportion, wt.%: sand 41.7–62 astringent 14.4–27.8 water rest 2. A method for preparing a backfill mixture of a given consistency, including dosing components containing a binder, water, wet aggregate, including sand and coarse aggregate, mixing them in mixing equipment to obtain a backfill mixture, followed by checking the consistency of the specified mixture, characterized in that before dosing the components, the sand used is divided into geological differences depending on its physical and mechanical properties, then flow charts are formed with the given costs of the components of the filling mixture with a set step for the flow, choose a flow chart that is closest in terms of the consumption of the components of the geological difference of sand at the entrance to the technology for preparing the filling mixture, measure the natural moisture content of the aggregate, at the same time, according to the value of the specified moisture, the number of dosed components is recalculated, and according to the value of natural moisture, the actual composition of the filling mixture is recalculated, measure the consistency of the filling mixture, compare it with the value of the specified consistency, if the result of the measurement of the consistency deviates from the given consistency, change the value of the specified moisture content to a lower or greater side from the previously set value with the possibility of achieving a given consistency of the filling mixture, while the value of natural moisture is used as a starting point for the allowable deviation of the value of the specified moisture relative to the value of natural moisture within the step of the range for water flow between adjacent flow charts, while the components are used in the following proportion, wt.%: sand 29.9-40.0 astringent 9.79–23.2 coarse aggregate 20.0–26.65 water rest 3. A method for preparing a backfill mixture of a given consistency, including dosing components containing a binder, water, wet aggregate, including sand, mixing them in mixing equipment to obtain a backfill mixture, followed by checking the consistency of the specified mixture, characterized in that the composition of the components includes a plasticizer, before dosing the components, the sand used is divided into geological differences depending on its physical and mechanical properties, then flow charts are formed with the given costs of the components of the filling mixture with a set step for the flow, choose a flow chart that is closest in terms of the consumption of the components of the geological difference of sand at the entrance to the technology for preparing the filling mixture, measure the natural moisture content of the aggregate, at the same time, according to the value of the specified moisture, the number of dosed components is recalculated, and according to the value of natural moisture, the actual composition of the filling mixture is recalculated, measure the consistency of the filling mixture, compare it with the value of the specified consistency, if the result of the measurement of the consistency deviates from the given consistency, change the value of the specified moisture content to a lower or greater side from the previously set value with the possibility of achieving a given consistency of the filling mixture, while the value of natural moisture is used as a starting point for the allowable deviation of the value of the specified moisture relative to the value of natural moisture within the step of the range for water flow between adjacent flow charts, while the components are used in the following proportion, wt.%: sand 43.9-65.0 astringent 13.1–26.3 plasticizer 0.46–1.14 water rest 4. A method for preparing a backfill mixture of a given consistency, including dosing components containing a binder, water, a plasticizer, a wet aggregate, including sand and coarse aggregate, mixing them in mixing equipment to obtain a backfill mixture, followed by checking the consistency of the specified mixture, characterized in that the composition of the components includes a plasticizer, before dosing the components, the sand used is divided into geological differences depending on its physical and mechanical properties, then flow charts are formed with the given costs of the components of the filling mixture with a set step for the flow, choose a flow chart that is closest in terms of the consumption of the components of the geological difference of sand at the entrance to the technology for preparing the filling mixture, measure the natural moisture content of the aggregate, at the same time, according to the value of the specified moisture, the number of dosed components is recalculated, and according to the value of natural moisture, the actual composition of the filling mixture is recalculated, measure the consistency of the filling mixture, compare it with the value of a given consistency, if the result of measuring the consistency deviates from the given consistency, change the value of the specified moisture content to a lower or greater side from the previously set value with the possibility of achieving a given consistency of the filling mixture, while the value of natural moisture is used as a starting point for the allowable deviation of the value of the specified moisture relative to the value of natural moisture within the step of the range for water flow between adjacent flow charts, while the components are used in the following proportion, wt.%: sand 31.5-41.33 astringent 8.41–21.6 coarse aggregate 21.0–27.52 plasticizer 0.54–1.79 water rest 5. A method of preparing a filling mixture of a given consistency according to paragraphs. 1-4, characterized in that separate storage of sand of various geological differences is provided. 6. A method of preparing a filling mixture of a given consistency according to paragraphs. 1-4, characterized in that the measurement of the moisture content of the aggregate is carried out by the express method of displacement of water. 7. A method of preparing a filling mixture of a given consistency according to paragraphs. 1-4, characterized in that the calculation of dosed components and the calculation of the actual composition of the components of the filling mixture is carried out using human resources. 8. A method of preparing a filling mixture of a given consistency according to paragraphs. 1-4, characterized in that the calculation of the dosed components and the calculation of the actual composition of the components of the filling mixture is carried out by the process control system. 9. A method of preparing a filling mixture of a given consistency according to paragraphs. 7, 8, characterized in that the calculation of dosed components and the calculation of the actual composition of the components of the filling mixture is carried out according to the algorithm. 10. A method of preparing a filling mixture of a given consistency according to paragraphs. 1-4, characterized in that flow charts with specified component costs are installed in the program. 11. A method of preparing a filling mixture of a given consistency according to paragraphs. 1-4, characterized in that when the measured value of the filling mixture consistency exceeds or is insufficient to the specified value and the condition for approaching the step range boundary in terms of water consumption between adjacent flow charts is met, a transition is made to another flow chart with a lower or higher water flow. 12. A method of preparing a filling mixture of a given consistency according to paragraphs. 1-4, characterized in that after the dosed components enter the mixing equipment with a working mixing volume in the range ^of 1.5–3.5 m supplying productivity for the output of the mixture for 33.8-157 s, followed by checking the consistency of the resulting mixture. 13. A method of preparing a filling mixture of a given consistency according to paragraphs. 1-4, characterized in that the consistency of the mixture is determined by the diameter of the flow of the mixture on the Suttard viscometer. 14. A method of preparing a filling mixture of a given consistency according to paragraphs. 1-4, characterized in that the consistency of the mixture is determined automatically by the viscosity of the mixture.

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