Load-Haul-Dump (LHD) machines in mining

 

 

Diesel-driven LHDs are versatile and flexible in mining. They are used in several tasks in addition to production and development, such as cleaning the roads, material haulage etc. The loading system and the use of LHD machines greatly depend on the mining method. Loading from a stope into a primary crusher is usually done in one or two stages. The most common ways of loading and transporting in an underground mine are:

 

• Loading with an LHD from a stope or through draw points into the ore pass. The haulage distance is usually between 50 and 400 meters. Further load-ing with LHDs from the ore pass into the crusher, or chute loading into a train or a conveyor belt, which transports the ore straight to the crushing plant or into the ore pass which leads to the crushing plant

 

• Loading from a stope straight into the crusher or into the ore pass that leads to the crushing plant. Tramming distance is usually between 50 and 400 meters, but longer distances are also used.

 

• Loading from a stope into dump trucks, which transport the ore to the crusher or to the ore pass leading to the crushing plant. Tramming distance is usually under 100 meters.

 

• Loading from a stope into a train or a conveyor belt, which transports the ore pass, or straight to the crushing plant.

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Задания

 

 

1. Переведите текст на русский язык.

 

2. Ответьте на вопросы к тексту:

 

а) In what tasks are LHDs used?

 

b) What is a haulage distance in loading with an LHD from a stope or through draw points into the ore pass?

 

c) What loading types can you call?

 

3. Переведите на английский язык следующие предложения:

 

а) Система погрузки и использование LHD в значительной степени за-висят от системы разработки месторождения.

b) Существуют различные способы перевозки и погрузки руды при подземной разработке.

 

c) Дизельные LHD-погрузчики широко применяются в горной про-мышленности.

 

TEST № 15

 

 

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Trucking in Ramps

 

 

While ore production in a mine continues, ore reserves are gradually mined out, from one level to the one below. When mining passes the lowermost haul-age level, trains can no longer be loaded through chutes, and dump into crusher.

Developing a new haulage level another 400 m down and extend the shaft, move the skip station down is a time-consuming and costly adventure. To access lower levels, miners use the trackless machines. Ore production can continue downwards with the ramp as access to lower levels. Here the ramp substitutes for the shaft. The ore carried uphill on the mine trucks, through the ramp, finally dumping into the old haulage level storage pocket, passing the crusher on its way to skip filling.

The loaded trucks travel the ramp at low speed, in first gear, full engine power. Carrying ore on trucks is costly mode of vertical transport, furthermore, diesel engine are heavy polluters of the underground air. However, there is no

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alternative. If the ore flow from below stops, there is nothing to feed the concen-trator, the mine is forced to close.

Year after year, the ramp extends one loop after the other, further down in the ground. Costs for trucking the ore uphill increase, diesel smoke further bur-dens the mine’s ventilation plant.

 

Задания

 

 

1. Переведите текст на русский язык.

 

2. Ответьте на вопросы к тексту:

 

a) Why is developing of mine another 400metres down difficult?

 

b) Why can we say, that the ramp constitutes for shaft?

 

c) What are the disadvantages of carrying ore on trucks?

 

3. Переведите на английский язык следующие предложения:

 

а) Дизельные двигатели самосвалов загрязняют рудничный воздух

 

и оказывают дополнительную нагрузку на вентиляционную установку.

 

b) Наклонный подъездной путь, используемый при транспортировке (transport) руды, удлиняется петля за петлей каждый год.

 

c) Доступ к нижним этажам возможен только при использовании са-мосвалов.

 

TEST№ 16

 

 

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Blasting

 

 

Blasting and drilling are closely linked in mining and excavation today. Like drilling, blasting methods have been progressively improved. New explo-sives and detonating equipment have entered the market, making blasting more predictable and accurate in most restricted areas.

In underground and surface mining, the main purpose of rock blasting is to fragment and heap the excavated rock to make loading and haulage as easy as possible. The geological and mechanical conditions of the rock and some limita-tions (populated areas, industrial plants, hospitals etc) should determine the final blasting procedure, the blasting geometry, the type of explosive chosen and

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detonators. In a remote area, blasting may be restricted by the limited availabil-ity of explosives and blasting equipment.

Blasting is affected by the following variables:

 

• rock geological and mechanical properties;

 

• environmental and safety aspects;

 

• properties and availability of explosives;

 

• blasting geometry;

 

• detonator availability.

 

The rock conditions present factors that cannot be altered. Blasting safety can sometimes be enhanced by removing people, or isolating delicate equipment and structures. The surroundings should always be taken carefully into account. Explosives, ignition and blasting geometry are changeable factors.

 

Задания

 

 

1. Переведите текст на русский язык.

 

2. Ответьте на вопросы к тексту:

 

a) What variables of blasting can be altered and how?

 

b) How have new equipment and blasting materials changed the quality of blasting?

c) What may be limiting factors for blasting in remote areas?

 

3. Переведите на английский язык следующие предложения:a) Бурение и взрывные работы тесно (closely) связаны.

 

b) Мы можем увеличить безопасность взрывных работ посредством

 

эвакуации населения и изоляции хрупких структур.

 

c) Мы не можем изменить горно-геологические условия, которые влияют на взрывные работы.

 

TEST № 17

 

 

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