SERVICETechnical service

Powder Technology Indicators

1, chemical composition,

Including: SiO2, MgO style, CaO, Fe2O3, Al2O3, soluble in water, soluble in acid, water content, heavy metals.

2, physical indicators

Include: whiteness, particle size, ignition loss, specific surface area, specific gravity, see hanging weight proportion (loose), 325 mesh sieve residual capacity, oil absorption value, water absorption, PH value.

3, indicators and detection method is introduced:

SiO2: important component index to measure the purity of talc.

Water: JIS - 110 oc K5101 2 hours. Generally less than 0.5%


Whiteness of talc industry has two kinds of narrow and broad. Narrow whiteness is the general definition of whiteness, available blu-ray whiteness R457, Y, L *, gansu, whiteness to describe. Whiteness of generalized including dry and wet white degrees and hue. The so-called wet whiteness is talcum powder adding suitable amount of DMP (dimethyl phthalate) measured after whiteness.

Talcum powder of whiteness, due to the different raw material and the fineness of dry degree ranging from 50 to 100.

Pinguan is using a "Beijing Kang Guang WSD - 3 c" automatic whiteness meter, can detect the dry and wet white degrees, L value, a value and b value.

Note: the L value: lightness value (shade); A value: red value (red and green degree);

B value: value of blue (blue and yellow).


Particle size detection method of settlement method measuring average particle size and laser method DV50, DV98 and DV100 particle size.

DV50: powder sample accumulative granularity percentage reaches 50% of the particle size distribution. Its physical meaning is particle size is greater than its particles accounted for 50%, less than its particles are also accounted for 50%, the D50 also called the median size or median size. D50 commonly used to represent the average particle size of powders.

DV98: powder sample accumulative granularity percentage reaches 98% of the particle size distribution.

DV100: powder sample accumulative granularity percentage reaches of the particle size distribution..

Pinguan USES liaoning instrument research institute "the GSL - 101 - b Ⅱ laser particle size distribution tester" testing DV50, DV98 and DV100 particle size.

Settlement method of average particle size and mesh conversion formula: the average particle size = 3750 / mesh

Sedimentation method, laser method DV50 mean particle size, and DV98 size and mesh table:

Average particle size1294.83.831.81.5
DV50 particle size109876.5654.53.5
DV98particle size45381512107542.5

Ignition loss:

Sample and the temperature of 1050 ℃ calcination to quantitative determination of reduction.

Specific surface area:

By the average particle size conversion, the relative area of unit 1 g of powder. Size and the processing technology and fineness, purity is higher and the more fine particle size, the bigger the specific surface area.

Specific gravity: 2.7

See hanging weight proportion (loose) :

50 g of sample has in the calibration of the measuring cylinder in 100 cc, falling from height of 5 cm after 150 times of measurements.


8-10; By the production company in Italy HAANNA the HI8520 type determination of PH meter.

DOP absorption:

When adding DOP titration, until it becomes saturated state.

Sedimentation volume:

Put 15 g of sample 100 c. C with bolt in the measuring cylinder, add water to 100 c. C make it static after intense shaking, determine its subsidence volume after 1 hour

Oil absorption value:

JIS - K5101 join linseed oil titration until into squares.

Water absorption value:

Add water titration until began to flow.

325 mesh sieve residual quantity:

In wet 1000 g sample in 325 witnessed in the mesh filter