Questions of manufactured sand
1 What’s the manufactured sand?
After soil removal, crushing, screening processes, the rock, mineral tailing, industrial residue particle which grain size less than 4.7mm is called manufactured sand.
2 Manufactured sand in concrete
Concrete prepared with machine-made sand as a fine aggregate. At present, the production of manufactured sand in foreign countries is not less than 5 billion tons per year, large-scale projects, civil housing are basically using manufactured sand concrete.
3 Manufactured sand standards
The items that need to be examined generally are fineness, grain grade, stone powder content, apparent density, void fraction, crushing value, methylene blue MB value and so on.
Manufacturing sand is usually made of granite, basalt, river pebbles, pebbles, andesite, rhyolite, diabase, diorite, sandstone, limestone and so on. hardness and application varied with rock type and crushing method.
5 Natural river sand VS manufactured sand
Appearance: manufactured sand has sharper edges, rougher surface.
hardness: river sand is harder than the manufacturing sand.
powder: the powder content of manufactured sand is higher.
manufactured Sand has better adhesion, better compression resistance and longer service life;
Fineness Modulus, manufactured sand can control the fineness according to the requirements, river sand has a variety of hardness gradation.
6 Mountain sand VS sea sand VS river sand
In general, Mountain sand has a higher content of mud, impurities. sea sand always contains shells and chloride, sulfate, magnesium salt which will cause corrosion of steel bars. all, in brief, the quality of river sand is better than the mountain sand and sea sand.
7 Grains gradation and fineness modulus
grain gradation: particle size distribution of the proportion.
fineness modulus: an index reflecting the fineness of manufactured sand, the greater the fineness modulus, the coarser the sand. There are four fineness of modulus(Mx): coarse, medium, fine and ultra-fine.
1) coarse sand, Mx is 3.7-3.1, the average grain size is over 0.5 mm;
2) medium sand, Mx is 3.0-2.3, the average grain size is 0.5 mm-0.35 mm;
3) fine sand, Mx is 2.2-1.6, the average grain size is 0.35 mm-0.25 mm;
4) super fine sand, Mx is 1.5 — 0.7, the average grain size is less than 0.25 mm.
8 Factors affecting manufactured sand
Feed grading, feed rate, crusher speed, screen size, etc.
9 Acicular sand and flaky particle sand
If the length of the manufactured sand particle is 2.4 times larger than the average particle size, this is called acicular type or needle type sand. The flake type sand means that its thickness is 0.4 times less than the average thickness. The average particle size refers to the median of the upper and lower limit of the particle size.
10 Sand aggregate
Aggregate is a general designation that the sand, gravel, gravel, rubble, rubble, stone and other materials in the construction site.
Aggregate with a particle size larger than 4.75 mm is called coarse aggregate, which is commonly referred to as stone or crushed stone.
Aggregate with a particle size less than 4.75 mm is called fine aggregate, also known as sand or manufactured sand.
Sand aggregate is the main building material of concrete and stone building in construction engineering.
11 Manufacturing rock sand technology
1) according to the way of separating stone powder, it can be divided into “wet sand making”, “dry sand making” and “semi-dry sand making”
2) according to the sand making process, it can be divided into “single sand making” and “combined sand making”.
3) according to the structure, it can be divided into “plane type sand making” and “floor type sand making”.
12 Machines of the manufactured sand processing plant
Common manufactured sand plant layout as follows:
jaw crusher + impact crusher
jaw crusher + cone crusher
jaw crusher + roller crusher
jaw crusher + impact crusher + vertical shaft crusher(barmac)
jaw crusher + cone crusher + sand making machine
13 Sand manufacturing process
rock – coarse crushing -medium crushing – fine crushing – screening – dust removal – manufactured sand.
JXSC mining machinery factory supply sand making machine, sand washing machine since 1985，contact us to get the construction material manufactured sand machine price and other stone crusher price.