Sericite mica

I. Structure and chemical composition of sericite mica
The Sericite mica is one kind of natural fine grain muscovite mica, is subspecies of muscovite, is the laminated structure silicate, the structure clamps an alumina octahedron constitution duplicate silica level by two silicas tetrahedrons (to see chart one). {001} cleaves completely, may deduct the extremely thin laminated shape, the piece thick may reach below 1u (theoretically to be possible to hew 0.001u), the big ratio of diameter to thickness. Compares with muscovite mica: has the natural particle size small, is easy to process the superfine characteristic. The sericite mica crystal chemical formula is: K_0.5-1(Al,Fe,Mg)₂(SiAl)₄O₁₀(OH)₂▪nH₂O,, General chemical composition: SiO₂ 43.13~49.04%， Al₂O₃ 27.93~37.44%，  K₂O+Na₂O 9~11%，H₂O 4.13~6.12%。

II. Physical property of Sericite mica
The Sericite mica belongs to the monocline crystal, the crystal for scaled, has silk-like the luster (muscovite mica to assume glassy luster), the pure block assumes grey color, the purple rose color, the white and so on. The aspect ratio >80, specific gravity 2.6~2.7, hardness 2~3, rich elasticity, easy curving, the abrasion resistance and the resistance to wear are good, the higher heat-resisting insulation, is difficult to dissolve in the acid and alkali solution, the chemical property is stable. Test data: The elasticity coefficient is 1505~2134MPa, heatproof quality 500~600 oC, thermal conductivity 0.419~0.670 W.(m.K)-1, electric insulation properties 200kv/Mm, anti- radioactive 5×1014 thermal neutron/ cm22 to degree of illumination.

Moreover, with similar mineral composition and structure to Kaolin, sericite mica also has some properties of clay, as good dispersibility in aqueous medium and in the organic solvent, certain viscosity, white color and fine granular. Therefore, sericite mica has many kinds of characteristics not only mica mineral and also clay mineral

III. Classification and distribution of domestic sericite mica ore deposit
Sericite mica mineral reserves rich resouces in China, distributed also broad, but the deposit worth developing and use are few. According to the sericite mica ore deposit origin, divides into generally the sheet sericite mica ore deposit (Anhui sericite mica ore), the porphyry alteration sericite mica ore deposit (Jiangxi porcelain quarry), the volcanic rock alteration sericite mica ore deposit , the secondary aposandstone illite sericite mica ore deposit (east Zhejiang volcano detritus alteration illite sericite mica ore), the clay stone sericite mica illite ore deposit. All of these sericite ores, the sheet sericite mica ore has highest development value, because mica characteristic of this kind sheet sericite mica ore is most obvious.

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Processing method and product Characteristic for sheet sericite mica

General domestic sheet sericite mica mine is formed due to the role of regional nature. Mineral composition is relatively simple, the main ingredients are sericite mica and quartz, about 50% two components each. Ore appears delaminated structure, likes crystal structure of flake-granite, has the exterior of a silken luster, a hand out smooth and grease. The current process generally are divided into dry and wet two kinds of methods.

Dry method
Processing principle: Under the effect of the mechanical power and wind power, the raw ore causes hit, cut and friction each other between the material and the medium, thus causes the material particle to become fine.
Production technology: see color picture

Wet method
Processing principle: Under the aqueous medium condition, the sericite mica and the quartz are stripped by roller grinding and stripping. Next, through hiting mutually and cutting, causes the material granular to become small. Last, remove the sand through the water power eddy to make the sericite mica granular to be concentrated.
Production technology: see color picture

Performance difference between dry and wet method of sericite mica
Main difference between the dry and wet method process lies in:
Dry process is unable to reject mineral impurity and so on associated the quartz, the product purity low, the quality fluctuation big, what is more essential is the sheet structure of sericite mica but is destroyed because dry- grinding, affects the product quality and the application. The wet method process after the dressing, except mixed concentrates, product purity high, quality stable, at the same time the sheet structure obtains well protects, ratio of diameter to thick big. Therefore t wet method process product receives more attention.
Characteristic of wet method sericite mica:
1. The stripping and flaking off by wet process, the sheet structure maintenance complete, ratio of diameter to thick is big.
2. Removing sand, the flotation selection and concentration by wet process, the purity of sericite mica is high;
3: Stripping and superfining by wet process, the granularity is thin also the scope of size controls narrow;
4. De-iron and bleaching by wet process, whiteness of product enhances above 10% than dry process.
■ Properties contract table between dry and wet method

Technology		Dry method	Wet method
Properties
Granular size		100-600 mesh	425-5000 mesh
Sericite mica %		40-60%	80-98%
Other composition	SiO2（%）	65-75	50-58
	Al2O3（%）	13-18	26-30
	K2O（%）	4-7	7-9
Ratio of Diameter to thickness		15-24	50-80
Whiteness O		65-72	78-82
Bulk density g/ml		0.4-0.6	0.25-0.35
Carbonate salt		0.5-10%( uncertain )	Zero

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Processing method and product Characteristic for sheet sericite mica

General domestic sheet sericite mica mine is formed due to the role of regional nature. Mineral composition is relatively simple, the main ingredients are sericite mica and quartz, about 50% two components each. Ore appears delaminated structure, likes crystal structure of flake-granite, has the exterior of a silken luster, a hand out smooth and grease. The current process generally are divided into dry and wet two kinds of methods.

Dry method
Processing principle: Under the effect of the mechanical power and wind power, the raw ore causes hit, cut and friction each other between the material and the medium, thus causes the material particle to become fine.
Production technology: see color picture

Wet method
Processing principle: Under the aqueous medium condition, the sericite mica and the quartz are stripped by roller grinding and stripping. Next, through hiting mutually and cutting, causes the material granular to become small. Last, remove the sand through the water power eddy to make the sericite mica granular to be concentrated.
Production technology: see color picture

Performance difference between dry and wet method of sericite mica
Main difference between the dry and wet method process lies in:
Dry process is unable to reject mineral impurity and so on associated the quartz, the product purity low, the quality fluctuation big, what is more essential is the sheet structure of sericite mica but is destroyed because dry- grinding, affects the product quality and the application. The wet method process after the dressing, except mixed concentrates, product purity high, quality stable, at the same time the sheet structure obtains well protects, ratio of diameter to thick big. Therefore t wet method process product receives more attention.
Characteristic of wet method sericite mica:
1. The stripping and flaking off by wet process, the sheet structure maintenance complete, ratio of diameter to thick is big.
2. Removing sand, the flotation selection and concentration by wet process, the purity of sericite mica is high;
3: Stripping and superfining by wet process, the granularity is thin also the scope of size controls narrow;
4. De-iron and bleaching by wet process, whiteness of product enhances above 10% than dry process.
■ Properties contract table between dry and wet method

Technology		Dry method	Wet method
Properties
Granular size		100-600 mesh	425-5000 mesh
Sericite mica %		40-60%	80-98%
Other composition	SiO2（%）	65-75	50-58
	Al2O3（%）	13-18	26-30
	K2O（%）	4-7	7-9
Ratio of Diameter to thickness		15-24	50-80
Whiteness O		65-72	78-82
Bulk density g/ml		0.4-0.6	0.25-0.35
Carbonate salt		0.5-10%( uncertain )	Zero

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Technical data of wet method sericite mica（Standard Q/GR 001-2004）

Index	GA-1	GA-2	GA-3	GA-4	GA-5	GA-6	GA-8
Fineness(mesh)	425	800	1000	1250	1500	2000	4000
Whiteness(O)	76±1	77±1	77±1	79±1	79±1	79±1	80±1
Oil absorption	28-32	30-35	40-45	33-38	40-45	42-48	55-75
PH Value	5-7	5-7	5-7	5-7	5-7	5-7	5-7
Moisture(%≤)	1.0	1.0	1.0	1.0	1.0	1.0	1.0
+ 325 mesh remain rate(%≤)		1	0.5	0.4	0.2	0.1	0.1
SiO2（%）	60-68	55-58	52-58	52-58	50-55	47-54	47-54
Al2O3（%）	18-25	25-28	25-28	25-29	26-30	27-32	27-32

Remark：
1. + 325 mesh remain rate is inspected by wet sieve.
Oil absorption is inspected according to ISO787/5-1980。
2. The above data is regular specification, excluding special ones.

Technical data of dry-method and wind-selected sericite mica
(standard Q/GR 002-2004 )

Index	fineness	Whiteness O	PH	H2O%	+325 mesh %	SiO2	Al2O3
GB-1	200 mesh	65-70	6-8	≤1.0		60-68%	15-18%
GB-2	400 mesh	65-70	6-8	≤1.0	≤1%	60-65%	19-22%
GB-3	800 mesh	65-70	6-8	≤1.0	≤0.8%	60-65%	20-25%

Remark：The above data is regular specification, special specification may be processed as per client’s requirement, subject to report of inspection