Fireclay Refractory Beneficiation
Fireclay is a kind of refractory mineral found naturally in the earths crust. It is composed of clay minerals (mostly kaolinite) and is usually found in sedimentary rocks formed and hardened by the presence of water. Fireclay is commonly of black, brown or white colors, depending on the amount of iron present.
Fireclay has been used for centuries to improve the performance and longevity of metal refractory products. In addition, fireclay is used to produce a wide variety of fireproof construction materials. Fire clay refractories can be found in everything from residential, commercial and industrial furnace masonry to cement-bonded ceramic bricks, tiles and block.
The term fireclay is used to describe all types of clay that can withstand temperatures of up to 2000°F (about 1100°C) and are suitable for use in the manufacture of refractory products. Fireclay refractory beneficiation is the process of separating and sorting fireclays into grades based on their individual characteristics. This is done to ensure that only those fireclays that possess all of the necessary qualities are used in production.
Fireclay refractory beneficiation involves separating the clay mineral into three different types: pelletized fireclays, crushed fireclays, and intact fireclays.
Pelletized fireclays are produced by crushing and separating them into fractions of different sizes. These fractions are then further divided into individual pellets and graded according to their size and purity. Pelletized fireclays are used for making high-quality, fire resistant masonry products.
Crushed fireclays are similarly produced by crushing the fireclay into different sizes, but the particles are not separated into individual pellets. Crushed fireclays are useful for making construction materials and masonry bricks but are not suitable for high-temperature refractory purposes.
Intact fireclays are the clay minerals that are not crushed and separated into pelletized or crushed fractions. The intact fireclay minerals are used in their original granular form because they contain the highest amount of refractory minerals.
Fireclay refractory beneficiation is carried out either manually or by using machines and is generally done in accordance with ASTM C1392, the standard for determining the properties of fireclay refractory products. During this process, a variety of tests and measurements are carried out to determine the suitability of the fireclay to be used in the production of refractory products.
The tests and measurements used in fireclay refractory beneficiation include measurement of bulk density of the fireclay, or the amount of fireclay per unit volume; determining the porosity of the fireclay, or the number of voids in a given volume of fireclay; and measuring the total organic content of the fireclay.
The ASTM C1392 tests also measure sediment index, mesh size, grain size distribution, and particle shape of the fireclay. These tests are important for determining the suitability of the fireclay for use in the production of high-temperature refractory products.
The most popular fireclays used in refractory products are those that have been pelletized and graded according to the ASTM C1392 standards. These fireclays have been tested and classified as either having a medium or high performance rating. Fireclays with a medium performance rating are suitable for use in applications where temperatures do not exceed 1750°F (1000°C). Fireclays with a high performance rating are capable of withstanding temperatures up to 2000°F (1100°C).
Fireclay refractory beneficiation is an essential part of ensuring the quality of fireclay used in refractory products used in a variety of industries. The process is used to separate fireclays into different grades according to their individual characteristics and levels of performance. This allows manufacturers to ensure that they are producing the best possible refractory products for their specific applications.
