ENHANCING THE ENVIRONMENTAL SAFETY OF THE YOSHLIK I QUARRY THROUGH THE IMPLEMENTATION OF AN INDIVIDUAL DUST SUPPRESSION SYSTEM ON DUMP TRUCKS

АННОТАЦИЯ

В данной статье рассматриваются методы пылеподавления в карьере «Ёшлик I» с акцентом на внедрение системы индивидуального пылеподавления карьерных автосамосвалов БелАЗ 75131. Анализируются основные источники запыленности, такие как буровзрывные работы, транспортирование и складирование горной массы, а также предлагаются современные технологии для их минимизации.

ABSTRACT

This article examines dust suppression methods in the "Yoshlik I" open-pit mine, with a focus on implementing an individual dust suppression system for BelAZ 75131 mining dump trucks. The main sources of dust pollution, such as drilling and blasting operations, transportation, and stockpiling of mined material, are analyzed, and modern technologies for their minimization are proposed.

Ключевые слова: пылеподавление, карьер «Ёшлик I», автосамосвал БелАЗ 75131, система орошения, запыленность, горное производство, индивидуальное пылеподавление.

Keywords: dust suppression, "Yoshlik I" open-pit mine, BelAZ 75131 dump truck, spraying system, dust pollution, mining operations, individual dust suppression.

Introduction

In modern conditions, mineral extraction is accompanied by significant dust formation, which negatively impacts the environment and workers' health. The dust generated during open-pit mining operations—such as drilling and blasting, excavation, transportation, and stockpiling of rock mass—poses a particular hazard. At the "Yoshlik I" quarry, this issue is especially relevant due to the high level of dust emissions during its operation. Therefore, the development of effective dust suppression methods is one of the key tasks in the mining industry.

Materials and Methods

Impact of Dust Sources on the Environment

Mineral extraction is accompanied by the formation and release of dust, which has harmful effects on the health of mine workers, leads to the premature wear of equipment, results in the loss of valuable mineral resources, and contributes to environmental pollution [1].

The main sources of dust emissions in stone quarries include technological transport delivering raw materials from the mining face to the crushing and sorting plant, as well as the crushing and sorting units themselves, loading and unloading points. If dust control measures are not implemented, workplace air pollution levels can exceed the established norms several times over. Therefore, combating dust in open-pit mining, including on roads, remains a pressing issue. Various auxiliary means are being researched and developed in this field [2].

The mining industry has a significant impact on the natural environment, inevitably causing its transformation. Dust control in quarries is one of the critical issues in ensuring safe working conditions for miners and protecting adjacent territories, as dust poses a serious hazard. The main dust sources include drilling rigs, drilling and blasting operations, excavators, dump trucks, conveyor systems, bulldozers, crushers, screening installations, and haul roads [3].

Almost all production operations performed in quarries (blasting, drilling, excavation, transportation of rock mass, and stockpiling) contribute to dust formation. Massive dust emissions occur during large-scale blasts, reaching 100–250 tons. Dust clouds from such explosions can rise to heights of 150–300 meters, expand up to 16 km, and spread over long distances (10–14 km) depending on wind direction [4].

Dust emissions are also significant during the transportation of rock mass in quarries, especially when using haul trucks. In coal mines, dust emissions reach 3000–4000 mg/s, while in metal ore quarries, they range from 600 to 1200 mg/s [5].

To address this issue, mining and processing enterprises must develop new dust suppression methods, as dust is the primary pollutant released into the environment alongside carbon monoxide.

Dust Suppression Methods

• Various methods are used to control dust emissions in quarries, which can be categorized as follows:
• Mechanical methods: These include the use of enclosures, wind protection screens, and special structures to minimize dust dispersion.
• Physico-chemical methods: Special reagents, such as aqueous salt solutions or foaming agents, are used to facilitate dust particle settlement.
• Hydraulic methods: Sprinkler systems and water curtains are employed to moisten surfaces, reducing dust suspension in the air.
• Organizational measures: These involve optimizing equipment movement routes, limiting vehicle speeds, and ensuring timely road and stockpile cleaning.

During transportation, the following primary and additional dust suppression measures are applied:

•  Adjusting the intervals between vehicle movements.
• Moistening or binding dust on road surfaces using binding additives.
• Reducing vehicle speeds.
• Periodic removal of worn surface layers using vacuum-equipped cleaning machines (widely used in Finland and Sweden in construction material quarries, but not commonly applied in coal mines).
• Preventing dust dispersal from truck beds by using protective covers or reducing the exposed surface area of dust-generating materials [6].

Results and Discussion

Dust Suppression Technology for BELAZ Trucks

This study proposes the implementation of an individual dust suppression system for mining dump trucks transporting rock mass during overburden removal and mining operations at the "Yoshlik I" quarry. High dust concentrations in the air significantly reduce vehicle speed, cause increased engine wear, and contribute to accidents. Prolonged exposure to a dusty environment may lead to occupational lung diseases. These negative effects can be eliminated or minimized with the proposed individual dust suppression system for each vehicle.

This system includes:

• Installation of 5 m³ water tanks on the sides of the dump truck.
• Spray nozzles with adjustable dispersion, positioned around the perimeter of the truck bed.
• A pump system with automatic control, activated when the vehicle is in motion.

At quarries, BELAZ 75131 dump trucks with a 130-ton payload capacity are used for rock mass transportation. These vehicles are the primary sources of dust emissions. Therefore, the system development and parameter calculations will be based on this model. Figure 1 presents the overall dimensions of the dump truck.

Figure 1. Overall Dimensions of the BELAZ 75131 Dump Truck

The individual dust suppression system for the BELAZ 75131 includes a fogging system designed to suppress airborne dust generated during the vehicle's movement.

Figure 2 presents the hydraulic schematic diagram of the proposed dust suppression system for installation on the BELAZ 75131, with a detailed explanation of all its components.

Figure 2. Schematic Diagram of the Individual Dust Suppression System for the BELAZ 75131 Mining Dump Truck:

1 - Water tank (platform canopy); 2 - Ball valve; 3 - Low-pressure pipeline; 4 - Flexible low-pressure hose (RVD); 5 - Coarse filtration filter; 6 - Pump unit with an integrated fine filtration filter; 7 - High-pressure pipeline; 8 - T-shaped connector; 9 - Flexible high-pressure hose (RVD); 10 - Rear spray rail with nozzles; 11, 13 - Water mist formation; 12 - Front spray rail with nozzles; 14 - Rear platform support hinges; 15 - Dump body; 16 - Service platform; 17 - Vehicle frame; 18, 19 - High-pressure pipeline.

Without altering the overall dimensions of the vehicle platform (length, width, and height), a tank will be fabricated on the platform canopy using sheet metal with a thickness of at least 10 mm through welding.

Given the required tank volume for dust suppression V = 2.1 m³ (see section 3.2) and the platform canopy dimensions a = 2.88 m, b = 6.3 m, the necessary height h will be determined.

Figure 3. Platform with a Water Tank on the Canopy A water tank is installed on the platform canopy, along with a filling neck:

1 - Platform; 2 - Filling neck with a locking cover; 3 - Platform canopy (water tank) with a sealed hatch (Figure 4).

The filling neck must be securely closed to prevent the ingress of rock material into the water tank during the loading of the dump truck by an excavator (Figure 4).

Figure 4. Filling Neck of the Water Tank for the BELAZ 75131 Mining Dump Truck:1 - Lid; 2 - Locking mechanism; 3 - Tank; 4 - Lid lifting handle; 5 - Hinged mechanism; 6 - Filling neck

Given the overall dimensions of the platform canopy (6300 × 2850 × 280 mm), we will calculate the actual volume of the canopy tank, taking into account the thickness of the sheet metal. In Figure 5, the internal dimensions, excluding the tank walls, are shown in parentheses. The sheet metal thickness is 10 mm.

Figure 5. Dimensions of the Canopy Tank Considering Sheet Metal Thickness

The volume of the vehicle's tank will be calculated as follows:

Where: a – width of the tank

b – length of the tank

h – height of the tank

We assume the volume of the canopy water tank to be V = 4.6 m³.

Since the width of the tank exceeds 6 meters, additional structural reinforcement is required. To enhance the rigidity of the construction, the lower and side parts of the canopy platform will serve as the base, as they form a rectangular box.

To close the upper part of the tank, the width of the canopy will be divided into seven equal sections, and the width of a single sheet blank A will be calculated.

We will use a pipe with an outer diameter of 50 mm as the support element and cut it into pieces equal to the tank height H = 260 mm.

To determine the number of support elements and their spacing, we divide the length of the platform canopy into five equal parts.

The distance between the centers of the support elements will be 56 cm.

Since we know that one metal sheet, which will be used to cover the upper part of the tank, has a width of A = 0.897 m, the row of support elements along the length of the tank will be spaced 879 cm apart. This results in 6 columns and 4 rows of support elements, totaling 24 pieces (see Figure 6).

Figure 6. Arrangement and Size Series of Support Elements

The refueling station is designed to fill the tanks of 54 BelAZ 75131 dump trucks equipped with an individual dust suppression system. The capacity of each dump truck is 4.6 m³.

The water filling station is illustrated in Figure 7, where water is supplied through a K-60 pump (5) via the pipeline (9) and hose (11), entering the dump truck tank (16) through the filling neck (10).

We plan to combine fuel refueling with water filling for the BelAZ 75131 tanks without affecting the existing fuel refueling system.The fuel and water refueling process for the BelAZ 75131 is carried out as follows:

The mining dump truck approaches the water refueling station located at the assembly site (Figure 7). At the same location, the KAMAZ 740 fuel tanker is present. The driver of the BelAZ 75131 then refuels the truck with diesel fuel while simultaneously filling the individual dust suppression tank. By the time the diesel fuel refueling is completed, the water tank will also be filled. This process is repeated for each mining dump truck equipped with an individual dust suppression system.

Figure 7. Fuel and Water Refueling Diagram for the BelAZ 75131 Mining Dump Truck with an Individual Dust Suppression System:

1 - Water tank, 2 - Filling pipeline, 3 - Drain plug, 4 – Valve, 5 - K-60 pump, 6 - Support structures of the service platform, 7 – Ladder, 8 - Pump control button panel, 9 – Pipeline, 10 - Filling neck of the tank on the platform canopy, 11 – Hose, 12 - Service platform, 13 - Ladder stop, 14 - Concrete foundation of the service platform, 15 - Concrete foundation of the tank, 16 - Water tank of the BelAZ 75131 mining dump truck, 17 - KAMAZ 740 fuel tanker.

We will calculate the volume of the stationary tank, considering the need to refuel each BelAZ 75131 equipped with a dust suppression system, with a tank capacity of 4.6 m³. The total number of BelAZ 75131 trucks in operation is 54 units.

For watering roads during the summer, irrigation machines based on the BelAZ-76470 vehicle with a tank capacity of 32 m³ are used.

Initial data for calculating the additional fleet of irrigation machines: Tank capacity – 32 m³, Additional road length – 4 km, Average roadway width – 40 m. The additional irrigation area is S _irrigation =180,000 m².

According to the design standards for mining enterprises with open-pit development (VNTP 13-1-86), the technical water consumption rate is N=0.5N = 0.5N=0.5 L/m², with K=3K = 3K=3 applications per day.

The maximum daily water consumption is calculated as:

= 6 тumber of trips per day considering water refilling.

The accepted fleet of water-sprinkling machines consists of 6 vehicles with a tank capacity of 32 m³ each.

According to research, the dust emission intensity on roads is 0.014 kg/s.

Let's calculate the amount of water required to suppress 0.014 kg

Table 1.

Meanings

Thus, to suppress the dust generated during movement, the shift water consumption is 1684 liters per shift. Dust suppression is concentrated at the "tail" of the dump truck. To improve the reliability of dust suppression, additional nozzles will be installed on the front bumper, increasing the total water consumption by 25%.

Table 2.

Meanings

Water consumption will increase by 422 liters. The total shift water consumption for dust suppression will be 2,106 liters.Thus, the shift water consumption for a single BelAZ 75131 mining dump truck with an individual dust suppression system is considered to be 2,106 liters—the higher of the two calculated values.

Conclusion

The implementation of an individual dust suppression system on BelAZ 75131 dump trucks is an effective solution for reducing dust levels at the “Yoshlik I” quarry. The proposed system significantly minimizes the harmful effects of dust on workers’ health and the environment, while also extending the service life of mining equipment. The practical application of this project can contribute substantially to improving industrial and environmental safety in mining enterprises.

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