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. Fur-ther loading with LHD-s from the ore pass into the crusher, or chute load-ing 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 dis-tance is usually under 100 meters.

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

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 stop 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 зависят от системы разработки месторождения.

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

c) Дизельные LHD-погрузчики широко применяются в горной промышленности.

UNIT 15

Прочитайте текст и письменно выполните задания к нему.

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 low-ermost haulage 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 adven-ture. To access lower levels, miners use the trackless machines. Ore pro-duction 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 stor-age pocket, passing the crusher on its way to skip filling.

The loaded trucks travel the ramp at low speed, in first gear, full en-gine 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 alternative. If the ore flow from below stops, there is nothing to feed the concentrator, 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 burdens 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 400 metres 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 вентиляци-онную установку.

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

c) Доступ к нижним этажам возможен только при использова-нии самосвалов.

Не нашли, что искали? Воспользуйтесь поиском: