500-ton granite sand washing plant plan design
Xin'an County Stone Factory needs a set of sand washing syst…
Placer gold refers to the gold that the rock gold in the mountain body is washed by the river and separated from the quartz vein.
Because this kind of gold is as fine as sand, it is pretended to be placer gold.
The gold in the earth’s crust is scattered fine gold sand or gold slag, but there is a natural gold nugget, a condensate of placer gold in the riverbed that has been complexed by carbonic acid for millions of years.
Placer gold (river gold) is easy to mine, and the process of rock gold mining is relatively complex and arduous. Generally, a ton of ore can be mined to extract a few grams of gold.
1. natural heavy sand method.
2. engineering heavy sand method.
3. old mining investigation.
4. geological and geomorphological analysis.
5. geophysical prospecting and aeronautical new technical methods.
Among them, the first three methods are through sampling investigation to find out whether there is placer gold and directly determine whether it is mineralized or not, which belongs to the direct prospecting method, while the latter two methods are mainly through the analysis and evaluation of metallogenic conditions and the study of some characteristics of environment and sediments to infer the possibility of mineralization, which belongs to indirect prospecting methods.
Among them, geological and geomorphological survey is the basis of placer gold prospecting and analysis.
Usually in determining where to look for placer gold deposits and where to arrange sampling projects, the basis is mainly provided by geological and geomorphological analysis.
The specific methods of placer gold prospecting are introduced below.
1. Gold dredger mining method.
2. Mining method of construction machinery: it refers to mining placer gold deposits by digging and loading ore and rock by construction machinery such as mechanical shovels and bulldozers, and transporting ore and rock by belt conveyors, automobile scrapers and loaders.
It is suitable for use in arid areas.
3. Hydraulic machinery mining method: it is a continuous production process in which the mechanical equipment such as water gun, sand pump and water pump are used to complete the work of washing mining, transportation, washing and tailings disposal in turn by using the same flow.
1 When the work site is located in the alluvial layer,
① The part where the river valley or river bed changes from narrow to wide.
②The inner side of the river’s sharp turn.
③The part where the riverbed changes from steep to gentle.
④The back of the bedrock or boulder of the river bed, and under the dam.
⑤The outer edge of the sand mouth facing the water surface is protruding.
⑥The tributary merges into the mainstream area.
⑦The lower part of the sand pile or beach.
⑧ The top surface of the clay in the depression or loose layer of the bedrock of the river bed.
⑨ Unsorted gravel and coarse sand accumulation place.
2 When the work site is on the river terrace, attention should be paid to the lower gravel layer.
3 Pay attention to the following parts when the work site is on the slope or residual layer
①The background value of gold or the residual layer above the geological body with high sulfide.
②Slopes and residual layers in the anomalous circles of gold, arsenic, antimony, and mercury.
③Slope residual layer located in the foothills, slope foot, dry valley, depression, valley bottom, and valley edge.