Source: 12360 Customs Hotline
#高岭土的归类与检测 #
The plot of the recent hit "Sweeping The Storm Against Organized Crime" can be described as ups and downs and gripping, making us realize on the one hand the necessity of the central authorities to carry out the "special struggle against organized crime and evil forces", and on the other hand, we also realize the determination and strength of the central authorities to "crack down on umbrellas and break the net, sweep away criminal syndicates strictly, and do everything possible to eliminate evil forces".
In the process of chasing the drama, the editor accidentally encountered a familiar scene and a familiar name - "test" and "kaolin".
First of all, to answer a question that everyone may be concerned about, are these samples enough?
The answer is yes, the red soil sample in the stills is estimated to be 3 to 4g, plus other tires, other parts of the sample, put together more than 20 grams should be no problem.
The title of laboratory test is a manifestation of a historical evolution, and now the industry is mostly replaced by "analysis and testing", in the case of instrumental analysis as the main analysis and testing method, the specimen that is usually tested on the machine is often about 1g.
The use of energy dispersive X-fluorescence spectroscopy (EDXRF) in tax-related testing can achieve the purpose of non-destructive testing.
Using a small number of samples (less than 1 g), with the help of powder X-ray diffraction spectroscopy (XRD), we can obtain the phase information of the soil sample, and the presence of the "kaolin" substance in the figure is determined by this method. Regardless of procedural issues, our classification laboratory can complete the above tests and give ingredient information.
However, kaolin is not a special substance, on the contrary, it is an extremely common substance. From the stills, we can see that the sample is red soil, which indicates that the soil is rich in iron and aluminum. Laterite is a zonal laterite distributed in the humid subtropical areas of China, which belongs to the moderate desilication aluminum-rich ferroalite, and the clay minerals are mainly kaolinite, acidic, and low salt saturation.
Laterite, picture from the network
In other words, the description of the appearance status and composition information of the sample shown in the stills is consistent, but the description of "kaolin is special" is untenable, and changing the line to "the sample contains sulfur" or "the sample contains plaster" would be more rigorous.
# Kaolin in tariffs #
25.05 All kinds of natural sands
Sand containing kaolin is naturally produced by kaolinite weathering, and kaolinite minerals usually need to be purified by a series of processes such as crushing, washing, precipitation, magnetic separation, etc. to meet the requirements of subsequent applications, so it is rare to see natural sand with kaolinite as the main component.
25.07 Kaolin and similar soils, whether calcined or not
This catalogue includes kaolin and other clays, the main components of which are kaolin minerals such as kaolinite, terracotta and pearl clay, silicon-rich kaolinite and elolite. These calcined clays are also included in this category.
Kaolin, also known as terracotta, is a high-grade white or near-white clay used in the ceramic and paper industries. Sand containing kaolin is not included (heading 25.05).
1#2507.0010 Whether calcined kaolin or not
Subheading 2507.0010 kaolin is a kind of clay with kaolinite as the main component, often containing Eloshi, montmorillonite, quartz and other components. The main chemical composition of kaolin is aluminum silicate, which also contains a small amount of iron, titanium, calcium, magnesium, potassium, sodium compounds and other components, but the composition varies greatly from different origins. Kaolin itself is white, because of the impurities can be grayish white, gray, gray yellow, yellowish brown, gray-green, gray-black and so on. Soily or dense lumpy, with a pronounced slippery feeling when touched by the hand, the density is 2.2 to 2.6g/cm3. Easily dispersed in water or solution, it has strong water absorption, but does not expand. Its chemical properties are relatively stable, the acid resistance is also good, and it has a high fire resistance.
In addition to kaolin, which is mainly used in the ceramic industry, the paper industry is also the largest user of kaolin, and it is also used in rubber, plastics, chemicals, refractory materials and other industries.
This subheading does not include goods that are specifically listed in other tariff codes after calcination.
2#2507.0090 Calcined other kaolin-like soils
# Kaolin in the real world #
Kaolin is a non-metallic mineral, which is a kind of clay and clay rock dominated by Kaolinite clay minerals, named after the village of Gaoling in Jingdezhen, Jiangxi Province. Because it is white and delicate, it is also called dolomite.
Pure kaolin is white and delicate, soft soil, with good plasticity and fire resistance and other physical and chemical properties. Its mineral composition is mainly composed of kaolinite, eloite, jelly mica, Illite, montmorillonite and quartz, feldspar and other minerals. Kaolin is widely used, mainly for papermaking, ceramics and refractory materials, followed by coatings, rubber fillers, enamel glazes and white cement raw materials, and a small amount for plastics, paints, pigments, grinding wheels, pencils, daily cosmetics, soaps, pesticides, medicine, textiles, petroleum, chemicals, building materials, national defense and other industrial sectors.
Kaolinite, the characteristics of sedimentary rocks can be clearly seen
kaolin
Kaolin is best known for its use as a raw material for the production of porcelain, and the reason why Jingdezhen porcelain is famous is because Jingdezhen has high-quality kaolin as a raw material.
In addition to the ceramic industry, purified kaolin is also widely used as a filler for paper, plastics, rubber and other industries due to its high whiteness (mainly through calcination to remove impurities).
Kaolin ore before calcination
Kaolin obtained by calcination to remove impurities
In addition, kaolin is also widely used in the field of refractory materials, in the actual trade state, the kaolin used in the field of refractory materials is rarely in the original ore state, and usually after the process of homogenization, calcination, crushing, the physical state is as follows:
Calcined kaolin for refractory materials, usually variegated particles of 3 to 5 mm
The above is the kaolin that we will encounter during the review and inspection process, and there are some minerals that do not seem to be related to kaolin, but are actually kaolin.
1# gangue
Coal gangue is another name for coal kaolin, coal kaolin, as the name suggests, coal kaolin and coal are associated, in other words, coal production will produce coal kaolin, so China's Shaanxi Province, Ningxia Hui Autonomous Region, Shanxi Province, Inner Mongolia Autonomous Region and other places are produced in large quantities.
2# Ball Clay
Ball clay refers to clay minerals with microcrystalline kaolinite and α-quartz particles as the main mineral components. Or pebble, a refractory raw material. Spherical clay is a highly malleable clay rich in organic matter, named after the United Kingdom.
Originally, China imported ball clay for use in the ceramic field because it was not known that ball clay was a kind of kaolin, and since finding alternatives in China, imports have gradually decreased.
The above gangue and spherical clay should be classified as 25070010.
3# porcelain clay and clay
Both porcelain clay and clay are named after their uses, i.e. soil used to produce porcelain and soil used to produce pottery. The production of porcelain and pottery often requires different mineral raw materials, but in general, porcelain clay or clay is still most common in kaolin, followed by feldspar and Erieite minerals.
Therefore, porcelain clay and clay may be classified into 25070010, 25070090, 25291000, and 25309099 according to the actual mineral composition.
# Detect the kaolin in the world #
Kaolin is a non-metallic mineral with kaolinite minerals as the main component, and after XRD analysis, it usually matches the kaolinite phase and quartz phase.
Phase analysis chart: (1) Kaolinite (2) Quartz
The crystal chemical formula of kaolinite is 2SiO2· Al2O3·2H2O, its theoretical chemical composition of 46.54% SiO2, 39.5% Al2O3, 13.96% H2O, XRF analysis, the apparent ratio of silica and alumina content is about 1:1, silica is slightly more, alumina is slightly smaller, and a small amount of iron oxide and titanium dioxide.
If XRF and XRD test results are as above, then the sample may be an item under 2507.
Note: Some of the images are from the Internet
Contributed by: Tianjin Customs