| Ceramic proppant?specifications are the responsibility in the USA of the American Petoleum Institute (API) and the current standard is API RP 56.
These specifications are very demanding and as a result suitable deposits are limited. The limited availability of natural reserves which are suitable for frac sand production coupled with growing demand ensures a high price for any producers able to meet the API RP 56 frac sand specifications.
Natural sands must be from high silica (quartz) sandstones or unconsolidated deposits. Other essential requirements are that particles are well rounded, relatively clean of other minerals and impurities and will facilitate the production of fine, medium and coarse grain sands.
Ceramic proppant? must be >99% quartz or silica. Most silica sand deposits are either already being exploited or are at least known of due to the use of this material in many other industrial applications including glass making and filtration media.
High purity quartz sands are common in the USA. These are made up of some deposits that are currently being exploited, some which have been abandoned and others that are so remotely located that costs of transporting material render them commercially unviable.
The tight specifications for frac sands – especially in relation to roundness and sphericity – make many deposits unsuitable for frac sand production.
From the work currently being done in the production of frac sands it seems that older quartzose sandstones have a better chance of producing a good frac sand. However, it is possible to upgrade other deposits if carefully controlled.
According to bulk density, Ceramic proppant? is divided into: low-density, medium density, high-density. According to the anti-crushing strength, frac sand is divided into 52Mpa, 69Mpa, 86Mpa and 103Mpa three series. Specifications of frac sand are: 12-18 mesh, 12-20 mesh, 16-20 mesh, 16-30 mesh, 20-40 mesh between 30-50 mesh, 40-60 mesh, 40-70 mesh and so on. |
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