Clay and clay minerals represent the youngest minerals in the Earth’s crust. Clays are
irregularly distributed in lithosphere, as their concentration increases due to the
weathering, hydrothermal changes, including anthropogenic influences. Clay minerals
occur in all types of sediments and sedimentary rocks and are common in
hydrothermal deposits. The interdisciplinary character of clay science follows from the
information obtained from the methodology and theory of other natural and technical
Pha rắn của đất gồm nhiều thành phần có tỷ lệ thay đổi khác nhau như tinh thể sét và các khoáng phi sét (non-clay minerals), các loại đất sét phi tinh thể (vô định hình-noncrystalline), vật chất hữu cơ, và các loại muối kết tủa.
Polymer nanocomposites are commonly defined as the combination of a
polymer matrix and additives that have at least one dimension in the nanometer
range. The additives can be one-dimensional (examples include nanotubes and
fibres), two-dimensional (which include layered minerals like clay), or three-
dimensional (including spherical particles). Over the past decade, polymer
nanocomposites have attracted considerable interests in both academia and
industry, owing to their outstanding mechanical properties like elastic stiffness
and strength with only a small amount of the nanoadditives.
Almost 4000 years ago Egyptians and Babylonians
used aluminum compounds in various
chemicals and medicines. Herodotus mentioned
alum in the fifth century b.c. and Pliny
referred to “alumen,” now known as alum, as a
mordant to fix dyes to textiles around 80 a.d.
In 1754 Marggraf showed that a distinct compound
existed in both alum and clays. In 1761
the French chemist Guyton de Morveau proposed
the name “alumine” for the base in alum,
identified in 1787 by Antoine Lavosier as the oxide of a then-undiscovered element.
Beneficiation (or concentration) processes are gener-
ally used to upgrade the phosphate content by
removing contaminants and barren material prior to
further processing. A few ores are of sufficiently high
quality to require no further concentration. The natu-
rally occurring impurities contained in phosphate
rock ore depend heavily on the type of deposit (sedi-
mentary or igneous), associated minerals, and the
extent of weathering. Major impurities can include
organic matter, clay and other fines, siliceous material,
carbonates, and iron bearing minerals.
The specific process employed will depend on factors
such as the characteristics and constituents of the
potash ore and the market specifications.
Generally, the ore is reduced in size using a system of
crushing and grinding to liberate the different miner-
als from each other. This is usually followed by
desliming by intense agitation followed by flotation or
hydrocyclones to separate the fines consisting of clays,
dolomite and sand from the potash ore.