1. Overview of the origin of mineral deposits
From the analysis of the production characteristics of attapulgite in nature and its relationship with related minerals, it is a low-temperature mineral and an alkaline solution Chemical deposits crystallized from the combination of SiO2 and Mg, or solid-liquid equilibrium phase change minerals. It can preferentially crystallize in concentrated seawater or SiO2-saturated brine solution at 25-220°C, and is distributed in various geological environments. The formation mechanism may be that volcanic eruptions and erupted basalts, volcanic debris and terrestrial rock weathering materials are dissolved by water and brought into lakes. Under arid or semi-arid climate conditions, when the aqueous solution evaporates and concentrates to a certain concentration, it becomes weakly alkaline. Attapulgite crystallizes directly from the solution. At the same time, calcite, dolomite, illite, smectite, quartz, opal, etc. are formed at different stages and conditions, forming different types of attapulgite clay deposits. In nature, it is common for phyllosilicates such as montmorillonite, illite, kaolinite and chlorite to transform into attapulgite. They are solid- Liquid phase transition.
It is generally believed that sepiolite is also a product of low-temperature chemical deposition or solid-liquid equilibrium phase change. The water medium condition during crystallization is an alkaline solution rich in magnesium and silicon and poor in aluminum (pH value is about 8.5). The water chemistry type is equivalent to the bicarbonate type-magnesium sulfate subtype water medium in the sulfate deposition stage. The success of synthetic sepiolite provides a basis for the above inference. The test was conducted using two methods in an alkaline solution with pH ≥ 8. The test pressure was 101325Pa and the temperature was 25°C.
The conditions for the formation of sepiolite and attapulgite are basically similar, with the main difference being the aluminum and magnesium content and pH value in the medium. When the medium contains aluminum, the possibility of forming attapulgite is higher than that of sepiolite. The pH value of the medium in which sepiolite is generated is about 8.5, which is a narrow range, while attapulgite can be generated in a pH range of about 7 to 9, so attapulgite is more widely distributed than sepiolite in nature.
Frank-Kome, Neckiji and Klokova used sepiolite and attapulgite to conduct high-pressure tests and showed that when SiO2 is desorbed to a certain amount, the layered chain structure is transformed into a layered structure of talc and montmorillonite. Stone minerals, so sepiolite and attapulgite minerals are regarded as transitional composites of layered silicates such as talc or montmorillonite and SiO2. Similarly, these layered silicate minerals can also be transformed into sepiolite and attapulgite minerals under certain geological and physical and chemical conditions.
2. Mineralization control conditions
The formation of sedimentary sepiolite-attapulgite deposits with important industrial significance is mainly controlled by the following conditions.
1) The geological age of formation is generally relatively late, mainly in the late Paleozoic and Mesozoic and Cenozoic Era. The former, such as the shallow sea type in Hunan, Jiangxi, and Shaanxi in my country, was formed in the Permian. The latter include Spain, Northwest Africa, the United States, Japan, the Atlantic Ocean, the Pacific Ocean, the Mediterranean Sea, the Persian Gulf and eastern my country. The Paleo and Neogene are especially concentrated, with stable layers and wide distribution.
2) Controlled by narrow depressions and depressions near tectonic activity zones. They often appear on terrestrial weathering and denudation surfaces or submarine weathering and denudation surfaces, not far from source recharge areas. The rock composition that contains sepiolite-attapulgite can be a magnesian carbonate type that is not related to volcanism, or a continental volcanic-sedimentary type that is related to volcanism, or the seafloor of the modern ocean floor. sediment.
3) Terrestrial or marine depressions or depressions should generally meet the following conditions: ① Magnesium-rich, silicon-rich, aluminum-poor and super-salinity environment; ② Low- to medium-low-energy sedimentary environment ;③Alkaline and relatively reducing environment with pH=8~11;④Narrow small basin that is closed to semi-closed.
Except for deep sea areas, they are generally under arid to semi-arid climate conditions and have certain characteristics of evaporation and sedimentation.
4) It is obviously controlled by lithology. Regardless of the continental or marine sedimentary type, its lithology can be roughly divided into two categories: ① carbonate rocks that are not directly related; ② volcaniclastic-sedimentary sandy muddy rocks that are directly related to volcanic materials.
3. Main types of origin and geological characteristics of mineral deposits
Sepiolite or attapulgite deposits are clay minerals with sepiolite or attapulgite clay minerals as the main components. They may be formed during sedimentation and leaching-hydrothermal mineralization, among which sedimentation is the most likely to form large-scale industrial accumulations. According to the geological background of mineralization and the mode of mineralization, it can be roughly divided into two categories: sedimentary type and eluviation-hydrothermal type.
(1) Sedimentary sepiolite and attapulgite deposits
The deposits are produced in inland alkali lakes, salt lake basins, and alkaline basalts in structurally stable arid or semi-arid climate zones. Basin, shallow sea carbonate platform, tidal zone and other areas. Mineralization can occur in three stages: syngenetic, diagenetic and epigenetic. Sepiolite and attapulgite minerals can either crystallize directly from the solution by evaporation, or they can be produced from illite, chlorite, montmorillonite, kaolinite, sepiolite (or attapulgite), etc. Transformed. The ore bodies are produced in layered, layer-like, and lens-like shapes, and their appearance is consistent with the surrounding rock. The scope of mineralization is generally large, ranging from several square kilometers to hundreds of square kilometers. The ore is in the form of earthy, dense block, clastic, nodule, etc. The mineral content of ores is generally greater than 50%, and can reach more than 90% in some cases. Associated minerals include montmorillonite, illite, calcite, dolomite, quartz, opal, chert, kaolinite, sepiolite (or attapulgite), etc. The size of the deposit can range from hundreds of thousands to tens of millions of tons.
According to the differences in the ancient geographical environment when they were formed, they can be divided into two subcategories: continental sedimentary deposits and marine sedimentary deposits.
1. Continental sedimentary type
Mainly occurs in ancient or modern arid climate areas, semi-closed to closed continental sedimentary basins. This type can be divided into evaporative chemical deposition type and volcano-sedimentary type.
(1) Evaporation chemical deposition type
It is formed by evaporation-chemical deposition. The minerals are mainly provided by the weathering products of sedimentary-metamorphic rock series around the basin or related source areas. Whether the sediment is mainly attapulgite or sepiolite, or both are produced together, often related to the pH gradient of the alkaline medium, the relative content of magnesium, silicon or aluminum, and the size of the basin, etc. closely related. Generally, attapulgite is mainly produced at the bottom and edges of basins, and saponite and sepiolite are mostly formed near the center of the basin.
Mineral deposit example 1: Vallecas sepiolite deposit in Spain
Produced in Paleo and Neogene sedimentary basins. Sedimentary materials are mainly supplied by weathered materials such as marble, argillaceous slate, mica schist, quartzite, and gneiss in the Paleozoic and Mesozoic strata around the basin. The mineral deposits are nearly east-west-trending lenses and occur in carbonate sedimentary rocks dominated by dolomite in the Paleogene and Neogene systems. Sepiolite crystallizes directly during the depositional stage or from brine solutions in fracture zones. The length of individual fiber crystals of sepiolite or attapulgite can reach more than several millimeters, forming a felt-like complex. The sequence of minerals appearing in the mineral deposits from bottom to top is: sepiolite-sepiolite attapulgite illite-attapulgite illite. The clay is dominated by sepiolite, with a content of 95%, followed by attapulgite, montmorillonite, illite, calcite, quartz, etc. The chemical composition is generally (wB/): SiO2 (57.83), Al2O3 (4.36), Fe2O3 (0.61), MgO (22.38), H2O (10.26).
Ore deposit example 2: Attapulgite deposit in Cáceres, Spain
It is located in the structural depression in the western part of the Tagus fault basin caused by the Alpine movement. The basement of the depression is composed of Cambrian slate, etc., with Paleo and Neogene deposits on it, with a thickness of 1800m. The denudation area around the depression includes slate, hard sandstone, limestone, dolomite and volcanic tuff. The edge of the basin is clastic lithofacies, mainly composed of clastic minerals such as quartz, dolomite, chlorite, and muscovite. Toward the center of the depression, it gradually turns into a montmorillonite and attapulgite clay layer. This layer occurs in the transition zone between the clastic mineral zone and the central evaporite, that is, the outer zone of the carbonate and sulfate phase zones. Close to the center of the depression, there is a small amount of sepiolite and cristobalite in the transition zone. The mineral seam is about 4m thick.
Attapulgite accounts for 85% of the ores, followed by quartz, calcite, dolomite, saponite, illite, chlorite, kaolin, cristobalite, etc. Chemical composition of attapulgite clay (wB/): SiO2 (51.5), Al2O3 (10.3), Fe2O3 (2.26), FeO (0.52), H2O (14.4), H2O- (7.36).
(2) Volcanic-sedimentary type
Represented by Liuhe, Xuyi, Jiashan, Lai'an, Tianchang and other counties in the bordering areas of Jiangsu and Anhui in my country. Attapulgite clay layers are widely developed in large alkaline basalt layers in this area. The mineralized area reaches 2000km2, and dozens of mineral deposits have been discovered, forming an attapulgite clay mineral belt. The mineral belt is located to the east of the Tanlu Deep Fault Zone, at the junction of the Yangtze quasi-platform and the Sino-Korean quasi-platform, that is, in the fault basin between the Zhangbaling uplift and the Jinhu depression. The ore-bearing Paleo and Upper Neogene alkaline basalts are distributed along the Fangshan-Nvshan fault zone in the northwest. Neogene volcanic-lacustrine sedimentary rock series, generally 100 to 300m thick, in unconformable contact with the underlying Paleogene red sand shale. The basement of the rift basin is composed of metamorphic rocks of the Proterozoic Yuzhangbaling Group, sedimentary rocks of the Doushantuo Formation and Dengying Formation of the Upper Sinian System, and Mesozoic continental volcanic rocks.
Ore deposit example: Jiangsu Xuyi attapulgite clay deposit
Attapulgite clay occurs in the Xiacaowan Formation of the Neogene and Neogene, and is also sporadically distributed in the lower section of the Guiwu Formation, Liuhe Occasionally seen in the group. The Xiacaowan Formation is composed of a set of medium-grained olivine basalt, olivine basalt and semi-consolidated silty mudstone, siltstone, sandstone and clay layers. Among them, 1 to 4 layers of basalt are interbedded or interlayered with sedimentary rocks. Generally, Thickness 20~90m.
Attapulgite clay in the Xuyi area is produced in layered and lens-like shapes. It is generally 2 to 5m thick, hundreds of meters or more than a kilometer long, and is relatively large in scale. For example, the V clay layer in Huajiagang-Yongxiao Mountain has an indistinct rhythm and can gradually change into silty mudstone and gravel along the direction. There are terrestrial animal fossils in the clay layer, and an opal layer about a few centimeters to tens of centimeters thick often appears in the middle and upper layers. Its occurrence is consistent with the roof and floor surrounding rocks. The types of clay minerals include attapulgite clay, dolomite attapulgite clay, siliceous attapulgite clay, montmorillonite attapulgite clay, montmorillonite clay, sepiolite-containing attapulgite clay, etc. They have certain regularity in spatial distribution. For example, from Huajiagang to Yongxiao Mountain, the order is: silty mudstone - montmorillonite clay - attapulgite clay - sepiolite-containing attapulgite clay. Huajiagang contains more quartz clastic components and may be the edge of the sedimentary basin, while Yongxiao Mountain is close to the center of the basin (Figure 5-3).
Figure 5-3 Schematic diagram of the changes in the type of clay layer No. Ⅴ in Huajiagang-Yongxiao Mountain, Xuyi
The clay is off-white to light gray, relatively pure in quality, and has a relative density of about 2. It has strong water absorption and slippery feel. Earthy, dense massive, and brecciated ores are common. In the thin section, pseudo rhyme structure, microscopic polyfiber deformed crystal structure and microscopic tuff deformed crystal structure can be seen. The ore is dominated by attapulgite, followed by montmorillonite, quartz, hydromica, and occasionally sepiolite. Clayized basalt chips and mineral crystal chips can be seen in the ore, and some plate-shaped and wedge-shaped crystal chips have been attapulgized. There is a common phenomenon that montmorillonite is metasomatized by attapulgite. The parent rock material of the clay layer may be basaltic breccia tuff or sedimentary tuff breccia. Montmorillonite is the precursor of attapulgite clay, which is the result of further evolution of the former under the influence of alkaline basalt materials. From the above analysis, it shows that attapulgite and basalt have a close genetic relationship: ① There are basalt breccias of varying sizes in the attapulgite clay layer; ② After some basalts are weathered and decomposed into clay, the unique tubular shape of basalt still remains partially. Stomatal and almond structure; ③ The chemical composition of attapulgite clay is similar to that of floor basalt, and the main oxide content is similar (except that FeO, K2O, and Na2O are higher than clay, and SiO2, Fe2O3, and H2O are lower than clay). The above situation shows that the attapulgite clay deposits in the Xuyi area belong to the volcanic-sedimentary type.
2. Marine sedimentary type
(1) Marine sedimentary sepiolite deposit
This type is mainly found in the Permian carbonates in my country In rock formations or coal-measure formations, for example, Leping in Jiangxi, Liuyang in Hunan, Ningqiang in Shaanxi and other places. These areas are all late Paleozoic sedimentary depression areas. The magnesian claystone in which sepiolite occurs is a set of carbonate rocks, mainly micrite limestone, dolomitic micrite limestone, chert limestone, calc-magnetic shale and claystone, and often combined with siliceous rock. , associated with chert lenses (nodules or strips), belonging to a set of micrite limestone formations with high silica content. The ore body is produced in layered, layer-like, or lens-like shapes, consistent with the surrounding rock bedding, and with a gentle dip angle. The ore body is thousands of meters long, hundreds of meters deep, and several meters to more than ten meters thick. The main types of ores include marl-type ores, calcium-magnesia shale ores, and clay-type ores (derived from the weathering of the first two). The main minerals are sepiolite, attapulgite, montmorillonite, calcite, talc, followed by dolomite, kaolinite, chalcedony, illite, pyrite, chlorite, celestite, fluorite, etc.
China's Permian shallow marine sedimentary type has the following characteristics:
1) Mineral deposits are found in certain layers and the layers are stable. Sepiolite and "chrysanthemum stone" are closely related and belong to the same layer.
2) The ore-hosting rocks are shallow marine chert limestone, marl, calc-magnetic shale intercalated with limestone lenses, which are a relatively typical set of carbonate rocks.
3) In the chemical composition of the ore-hosting rock, the CaO content is high, the MgO content is relatively low, and it is poor in Al2O3. Among the samples dominated by sepiolite from Liuyang, Hunan, the MgO content is mostly 11.36 to 17.62, and the medium range is generally 5 to 11. When the MgO content is >20, talc transformed from sepiolite is dominant.
Example of mineral deposit: Yonghe sepiolite clay deposit in Liuyang County, Hunan
The mining area is located at the southwest end of the Pingxiang-Leping Late Paleozoic sedimentary depression area. The Proterozoic Sinian, Upper Paleozoic Devonian, Mesozoic Cretaceous, and Cenozoic Quaternary strata are exposed in the area. The igneous rocks are mainly medium-acidic rocks. The structural location is at the composite junction of Liuyang's "S"-shaped structure and the eastern section of the Anhua-Yonghe east-west trending structural belt, with nearly east-west trending folds and faults developed. The Permian system is mainly exposed within the mining area, forming a nearly east-west axial syncline structure. The axial strata are the Upper Permian Longtan Formation and the Lower Permian Maokou Formation and Qixia Formation. The north wing is the middle and upper Carboniferous Hutian Group, and the south wing is cut by regional east-west thrust faults (Figure 5-4).
The mineral deposits are produced in the upper marl section of the Qixia Formation of the Lower Permian System (Xiangtan, Xiangxiang, Ningxiang, Loudi and other places classify this layer as the bottom of the Maokou Formation). Both sepiolite and Liuyang chrysanthemum stone are produced in this layer. The ore-bearing layer is 40-70m thick and is closely related to chert limestone. The floor of this layer is 2-8m thick flint limestone, and the roof is Maokou limestone.
The ore bodies are produced in layered, layer-like or lens-like shapes, and their appearance is basically the same as that of the surrounding rocks. The ore-bearing layer extends for more than 3,000 meters (the maximum length is 6,000m), with a sloping depth of 300-400m, containing 2-4 layers of ore, with a layer thickness of 2-7m, and a maximum thickness of 16.34m.
The mineral combination is simple. More than 90% of the samples are composed of four minerals: sepiolite, calcite, quartz and talc, with the first two being the main ones. The secondary minerals include dolomite, kaolinite, montmorillonite, halloysite, chlorite, etc. Trace minerals include muscovite, zeolite, attapulgite, illite, etc. There is no obvious change in sepiolite above the shallow underground, but the content of talc is relatively high, which may be related to the weathering transformation of sepiolite. Due to weathering loss, the calcite content is low in the shallow parts of the underground and high in the deep parts.
There are two types of ore in the mining area: clay type and original rock type. The clay type is distributed on the surface and in shallow parts, and is formed by the weathering of sepiolite-containing marl and calcareous shale. Sepiolite has a high content, and is mostly dark gray, off-white, earthy, soft, with a jagged cross-section and a slippery feel. It has strong plasticity after absorbing water, and the pulping rate can reach 9.54~16.40m3/t. The original rock type is marl and calc-magnetic shale containing sepiolite, which is dark gray to gray black. It is in the shape of flakes and leaves, with low hardness. Generally, the sepiolite content is above medium, and the pulping rate is poor.
Figure 5-4 Simplified geological map of Yonghe sepiolite mining area
The chemical composition characteristics are: high CaO content, low MgO and Al2O3 content, and large changes in SiO2 content. According to statistics, the content of Al2O3, SiO2, Fe2O3, MgO, etc. is higher near the surface and decreases toward depth, while the opposite is true for CaO. When the MgO content is >20, it becomes mainly talc.
The lithology of the ore-bearing layer is composed of shallow marine chert limestone, marl, calc-magnetic shale intercalated with limestone lenses. The mineral-bearing layer produces a large number of shallow marine fossils such as tuna, brachiopods, and corals. The mineral seam has an integrated and gradual relationship with the upper and lower limestone and chert limestone.
Sepiolite and chrysanthemum stone are produced in the same layer and formed roughly at the same time. Chrysanthemum stone is a radial development of lapis lazuli around chert nodules. It is caused by the crystallization of strontium sulfate when seawater evaporates to a certain extent in a regression environment. Seawater in this environment is rich in magnesium and silicon but poor in aluminum. In alkaline water, magnesium ions combine with colloidal silica and precipitate, forming a carbonate rock-calcium-magnetic clay-type sepiolite deposit in shallow marine phases.
(2) Marine sedimentary attapulgite clay deposits are represented by Libria in Spain and Chelkas in Ukraine (which are related to bentonite deposits).
Example of mineral deposit: Attapulgite-sepiolite deposit in Liberia, Spain
This deposit is located in the Gualsville Basin, near the outlet of the Gualquivi River. The mineral deposits occur in lacustrine sediments on the continental margin during the Paleogene and Pliocene regression periods. The Pliocene strata are divided into three sections: the lower section is marine quartz sandstone; the middle section is marl-calciferous layer, 25-30m thick; and the upper section is attapulgite clay layer. The middle section produces chert, dolomite, attapulgite-sepiolite clay, which is sandwiched in chert-bearing limestone and marl in the form of layered lenses. The sepiolite content in clay is 20 to 60%, and attapulgite only accounts for a few percent. The sepiolite content is directly proportional to the quartz content and inversely proportional to the calcite content. The attapulgite clay layer in the upper section is sandwiched in the limestone. There is a layer of nodular limestone about 4 to 5 meters thick on the top of the limestone. The attapulgite content in the clay reaches 60 to 80%, which is proportional to the calcite content and contains only a small amount of sea foam. Stone, montmorillonite and illite, the ore layer is more than ten meters to hundreds of meters thick.
(2) Eluviation-hydrothermal attapulgite and sepiolite deposits
This type of deposit is generally produced in the form of veins in altered volcanic tuff, altered granite, serpentine In laminates and marbles, they are often filled in the cracks together with magnesite, chlorite, opal, calcite and other minerals. Such as Hubei Guangji, Henan Lushi, Inner Mongolia Bayan Obo, Sichuan Shimian County, Anhui Quanjiao, Shaanxi Shangxian and other places, as well as the Russian Transcaucasus (containing palygorskite tuff clay).
The Lalinzi sepiolite deposit in Shang County occurs in the Ordovician strata. The exposed rocks mainly include dolomitic marble, diopside marble and biotite gneiss, which are in contact with granite on the north, east and west sides. Sepiolite and calcite fill the cracks of dolomitic marble and appear in groups of fine veins. A single vein is 1 to 10 cm thick and does not extend much. There is also a small amount of quartz in the veins, and calcite crystal clusters can be seen in the geodes. Sepiolite is a white fibrous aggregate with fibers of varying lengths, the longest being up to 60mm. Sepiolite is unevenly distributed in the veins and mostly appears in the gaps between calcite particles. Restricted by the shape of calcite, its formation time is slightly later than that of calcite. Vertical vein wall growth of fibrous sepiolite can also be seen.
The attapulgite deposit in Quanjiao, Anhui Province is located 4.3km northeast of Machang, Quanjiao, on the east wing of the forearc of the Huaiyang Mountain-shaped structure, on the east side of the Tanlu Deep Fault, and to the northwest of the southwest end of the Yupingshan compound syncline in the county. wing. The marbles of the upper member of the Doushantuo Formation and the lower member of the Dengying Formation of the Sinian system are mainly exposed, and folds are developed in the northeast direction. In the early Yanshan period, complex rocks such as quartz monzonite and diorite porphyry, which were supersaturated with aluminum silicate, were intruded. The veins are produced in the fracture zones of dioritic breccia, brecciated granodiorite porphyry, marble and phyllite shale in the upper section of the Doushantuo Formation in the internal and external contact zones, and run in the northeast and north-northeast direction. Distribution, inclined to the southwest or southeast, with an inclination angle of 60° to 85°. Ore veins are produced in the form of fine veins and network veins. The attapulgite fibers in the veins are long, rich in content, and have few impurities. The composition of impurities varies with the properties of the surrounding rock. Diorite-containing clastic components present in diorite breccia, and calcite in marble.
There are five main veins, extending 25-100m and vein thickness 0.2-1.2m. The ore type is mainly fiber bundle structure, containing more than 90% of attapulgite. Followed by vein-filled metasomatic ores (containing attapulgite 30 to 60), reticular vein ores (containing attapulgite 30 to 60), and brecciated ores (containing attapulgite 30 to 80). The ore mainly has a fibrous structure, followed by metasomatic residual structure and intersecting structure, with massive, veiny and brecciated structures. The ore is pink-white, slightly rose-red after absorbing water.
Eluviation-hydrothermal sepiolite clay deposits are mainly produced in the cracks of magnesium-rich rocks, and are basically the same type of host rocks as hydrothermal attapulgite deposits. The technological performance of this type of ore is excellent, but the volumetric mineral content of the ore body is low, the scale of the deposit is small, and the industrial value is not great.
IV. Deposit Distribution
Sepiolite and attapulgite rarely form separate large accumulations. Because they have similar mineral structures and the same chemical composition, they are often produced together. In addition to China, the main producing countries include Spain, the United States, and Russia, followed by Turkey, Senegal, Somalia, Kenya, Greece, Japan and other countries.
Spain is the largest producer of sepiolite and attapulgite in Europe, and is currently the country with the richest sepiolite resources. Attapulgite and sepiolite are produced in two forms: one is produced in bentonite deposits. For example, in the bentonite deposit in Almeria, the strongly altered part contains a small amount of attapulgite and sepiolite (similar to those produced during the alteration). associated with excess magnesium). The other is a fuller's earth deposit composed of sepiolite, produced in the Tagus Basin.
The United States is the main producer of attapulgite. The mineral deposits are concentrated in the area between Georgia and Florida and are mostly of sedimentary origin. Often composed of a mixture of several clay minerals. In the attapulgite clay deposits of Georgia, there are also montmorillonite and sepiolite clays that occur as tabular crystals or discontinuous layers in the Miocene Hawthorne Formation. The sepiolite clay deposits in the United States are distributed in the Ash-Meadows area of ??Nevada and occur closely with Pleistocene calcareous, sodic and magnesian bentonites.
The first attapulgite fuller earth deposit available for mining in the former Soviet Union is located in Cherkasy, Ukraine. It has five layers of ore, with a single layer thickness of 1.5 to 8m, most of which are composed of montmorillonite. Composed, there is only one layer mainly composed of attapulgite (2m thick).
Turkey’s sepiolite deposits are formed by the alteration of forsterite-rich serpentinite or other magnesite rocks. The ore is in the form of dense blocks, and meerschaum appears as scattered nodules, which can be used to make cigarette holders, pipe linings and various decorations.
Most of my country's attapulgite clay resources are distributed in Xuyi-Liuhe, Jintan, Jiangsu and Mingguang-Jianxi, Anhui. Attapulgite clay has also been discovered in Inner Mongolia, Sichuan, Shandong, Guizhou, Gansu, Xinjiang, Hunan and other places. It is mainly produced in Neogene and Paleogene volcanic rock systems, Cretaceous continental strata, Ordovician and Permian systems. Among the limestone formations, Cambrian and Sinian dolomitic limestone, especially the Neogene and Cretaceous basalts are most beneficial to mineralization. Except for the Jiangsu and Anhui regions, the scale of industrial development of attapulgite clay in other regions is not large. Therefore, my country's attapulgite clay industry is actually represented by attapulgite clay in the Jiangsu and Anhui regions.
my country’s sepiolite minerals are widely distributed and there are many mineral deposits. The distribution of hydrothermal sepiolite minerals is mainly concentrated in the East Qinling area, except for Anhui Quanjiao. In addition, sepiolite has also been found in Guizhou, Yunnan Wuding, Hebei Zhangjiakou, Hubei Guangji, Sichuan Shimian County and other places. Sedimentary sepiolite minerals are mainly produced in the Permian carbonate rock formations, with a small amount occurring in the Lower Cretaceous. Mainly distributed in Liuyang, Xiangtan, Ningxiang, Wangcheng, Xiangxiang, Shimen in Hunan, Leping in Jiangxi, Ningqiang in Shaanxi, Tangshan in Hebei and other places. Among them, Yonghe in Liuyang in Hunan, Shitan in Xiangtan, and Daolin in Ningxiang are large deposits.