enow.com Web Search

Search results

1. Results from the WOW.Com Content Network

2. Crushed stone - Wikipedia

   en.wikipedia.org/wiki/Crushed_stone

   Crushed stone has one of the lowest average by weight values of all mineral commodities. The average unit price increased from US$1.58 per metric ton, f.o.b. plant, in 1970 to US$4.39 in 1990. However, the unit price in constant 1982 dollars fluctuated between US$3.48 and US$3.91 per metric ton for the same period.

3. Placer mining - Wikipedia

   en.wikipedia.org/wiki/Placer_mining

   The amount of gravel that can be processed using the Mexican dry wash technique varies from 1 1/2 to 4 cubic yards per day, and can be processed at a maximum efficiency of 80%. [18] Another form of dry washing is "winnowing". This method was most commonly used by Spanish miners in America, and only requires a blanket and a box with a screen on ...

4. Gravel - Wikipedia

   en.wikipedia.org/wiki/Gravel

   Gravel is classified by particle size range and includes size classes from granule- to boulder-sized fragments. In the Udden-Wentworth scale gravel is categorized into granular gravel (2–4 mm or 0.079–0.157 in) and pebble gravel (4–64 mm or 0.2–2.5 in). ISO 14688 grades gravels as fine, medium, and coarse, with ranges 2–6.3 mm (0.079 ...

5. Construction aggregate - Wikipedia

   en.wikipedia.org/wiki/Construction_aggregate

   In Europe, sizing ranges are specified as d/D, where the d shows the smallest and D shows the largest square mesh grating that the particles can pass. Application-specific preferred sizings are covered in European Standard EN 13043 for road construction, EN 13383 for larger armour stone, EN 12620 for concrete aggregate, EN 13242 for base layers of road construction, and EN 13450 for railway ...

6. Gravel pit - Wikipedia

   en.wikipedia.org/wiki/Gravel_pit

   Gravel pits are located where there are rich sources of materials suitable to be crushed into aggregate, often at sites of fluvial, glacial, or floodplain geological deposits. [4] Sedimentary and igneous rocks typically produce good quality aggregates of various sizes, but metamorphic rocks are rarely mined at gravel pits as they tend to have ...

7. Track ballast - Wikipedia

   en.wikipedia.org/wiki/Track_ballast

   A variety of materials have been used as track ballast, including crushed stone, washed gravel, bank run (unwashed) gravel, torpedo gravel (a mixture of coarse sand and small gravel), slag, chats, coal cinders, sand, [3] and burnt clay. [4] The term "ballast" comes from a nautical term for the stones used to stabilize a ship. [1]