Environmental Damage

From My Class Wiki

Contents 1 HYDRAULIC MINING 2 HARD ROCK MINING 2.1 Description 2.2 The Process 2.3 The Hazard 3 DREDGE MINING 3.1 The Machine 3.2 The Process 3.3 The Gold 4 References

HYDRAULIC MINING

Hydraulic mining was the most useful method of mining. The way they would use this method was that miners would put lots of water into ditches and channel ways. Then the water would go through the pipes that were made out of iron, and the water would explode out toward the mountain. The mountain would expose this precious metal. The dirt from the mountain was washed away into sluice boxes. Then the dirt was dumped into the river.

When too much dirt and gravel is dumped into the rivers, they can’t support plant life. Trees were also destroyed. When trees died out, many animals such as birds lost their homes. Then, other animals would die out because they had no food or shelter. Fish also suffered because some rivers were covered with about 100 feet of gravel.

Laws were soon passed to control this method of mining. Animals made a comeback, but rivers that were once beautiful, remain in the state they were because of hydraulic mining.

(Jessica April 3, 2008)

HARD ROCK MINING

Description

Hard Rock Mining used dangerous explosives to get down into the quartz sleeves in which are where the gold depsits are. The miners descended filling ore cars with quartz rock. This work was complicated by the fact that there were cave-ins, explosions, toxic fumes, and flooding. Many miners were killed.

The Process

The miners, next, had to extract, or separate, the gold from the quartz ore. The quartz was crushed using a stamp mill. Then, the fine grains of quartz were washed out, using mercury, called quicksilver^[1]at the time, leaving only the gold. The mercury washed down the mountains, despite the efforts the of miners who tried to recover the precious mercury.

The Hazard

Mercury is very toxic to all living things, so when the mercury washed into the rivers, fish, whales, and other animal deaths occured. Much mercury residue is left in the sediment settled on the of San Fransico Bay. This was a dangerous part of the gold rush.

(Henry April 17, 2008)

DREDGE MINING

The Machine

Dredges are lines of pails that pick up bucketfuls of dirt. The buckets could hold 18 sq ft. The dredges picked up 15,000 sq ft. It operates 24/7 only stopping for maintainence.

The Process

The gold from the load was extracted, or separated, and the waste products, called the tailings^[2], were dumped along the riverside. the piles turned into mountains, some measuring as tall as a seven-story building. You can see these huge mountains in various parts of the Sacramento Valley.

The Gold

The gold extracted each day was 125 mg of gold. That is why the moutains were so big, since it was because the dredges could make $7,000,000 in eight years.

(Henry April 18, 2008)

References