GB/T 4414-2013Methods of sampling and sample preparation of tungsten concentrates in bags (English PDF)

3.1 Batch and batch batchandbulk

Processed or produced under the same conditions as a certain quality of packaging a number of tungsten concentrates, quality constituting a group called bulk tungsten concentrates.

3.2 Pack difference packeterror

In packets sampled for its quality properties, the difference between the results of the package called package is poor, the difference between the highest and lowest results called it the largest

Pack difference.

3.3 Increments and increment amount sampleandsamplenumber

By a group of tungsten concentrates Packing a bag, a sample taken according to the provisions of quality, called increments. Each kind of quality parts called the increment amount.

3.4 Subsample duplicatesample

The parts individually or sample after crushing and reduced grouped batch of tungsten concentrate in two or more.

3.5 Large sample

All parts of the sample or all of a number of subsamples or tungsten concentrate samples were crushed one by one and shrink minutes after the composition of it.

3.6

Samples were prepared preparationofsamples

Predetermined sample preparation sample, subsamples from each sample parts or large sample prepared.

3.7 The sample composition

Removed from the sample preparation for analysis of sample components.

3.8 Water samples

Water from the bulk sample or subsamples prepared measurement sample points.

3.9 Maximum size

Sieve mesh size of about 5% of.

3.10 Error inaccuracy

The difference between the measured value and the true value.

3.11 Deviation

The difference between the measured value with a set of the average of the measured values.

3.12 Variance s2

Each time the difference between the measured value and the average value Xi of X squared and divided by the number of measurements n minus 1 of the difference.

s2 = sigma (Xi-X) 2 n-1 nsigmaXi2- (sigmaXi) 2 n (n-1) (1)

3.13 Standard deviation s

The square root of the variance.

3.14 Quality fluctuation standard deviation sW qualityfluctuationofstandarddeviationsW

Means the standard deviation between intra parts like quality properties fluctuate according sW value of the size of tungsten concentrates can be divided into quality fluctuations, the small three

Types. Quality fluctuation test methods shall comply with GB/T 2007.3 of.

3.15 Accuracy beta precisionbeta

The measured value of the degree of agreement with each other, the probability of 95%, twice the standard deviation accuracy of representation, i.e., beta = ± 2S.

The total accuracy betaSDM including sampling accuracy betaS, sample preparation and measurement accuracy betaD accuracy betaM.

betaSDM = 2 s

S s2D s2M (2)

Where.

sS --- sample standard deviation;

sD --- sample preparation standard deviation;

sM --- Determination of standard deviation.

Checking the accuracy of test methods shall comply with GB/T 2007.4 of.

4.1

standard provides total accuracy betaSDM of ± 0.6%, sampling accuracy betaS of ± 0.4%, to tungsten trioxide meter.

4.2

Packaging tungsten concentrate must be strictly in accordance with the method specified in this standard and sample preparation. When the event condition or change in circumstances should be GB/T 2007.4

Checked for accuracy test. When using mechanical sampling, should be GB/T 2007.3, GB/T 2007.4 test. Demonstrate compliance with regulatory standards

The request.

4.3

As obvious uneven quality, including more than 2% difference in moisture content than the standard (tungsten concentrate moisture content greater than 1% water containing synthetic scheelite

Greater than 4%), maximum particle size of more than 9mm or mixed with foreign substances, the sample will be processed after the finishing line.

4.4

Packaging and tungsten concentrates for the grant, the difference between similar products of tungsten trioxide content of the batch within ± 0.5% and batch can. And after the bulk

Not in batches.

4.5

composition of the sample should keep it for verification, according to the needs of the custody provisions, but not less than six months.

4.6

Sampling and sample preparation used equipment, tools and sample containers must be kept clean and filled, solid and durable.

4.7

Note that the safe operation of the entire sampling, sample preparation process.

4.8

Quality fluctuation test methods, checking the accuracy of test methods and test methods for sampling error checking respectively, according to GB/T 2007.3,

GB/T 2007.4 execution.

5.1 sampling tool

Sampling tools include.

a) Sampling shovel (see FIG. 1);

b) sampling stick (see Fig. 2);

c) Sampling spoon. 11.5cm diameter semicircular metal spoon;

d) covered bucket containing the sample;

e) steel hammer.

Millimeters

Figure 1 spatula sampling

Millimeters

Figure 2 sampling stick

5.2 parts by number of samples (sample packets)

Minimum number of samples to be taken as parts shown in Table 1. Part number of samples (n1) and different batches according to equation (3) Calculated.

n1 = n

Actual quantities

Basic batch (3)

Where.

The basic quantities of 10t (200 package), n should be taken as the basic minimum quantities of parts number of samples (see Table 1).

According to equation (3) the calculated minimum number of samples parts, if any rounded up to integers.

Table 1 some packaging parts shall be taken in Tungsten minimum number of samples

Batch/t Number/package

Parts of n number of samples

Quality small fluctuation sW (SW < 0.4)

Fluctuations in quality sW (0.4<=sW < 0.6)

Great quality fluctuations sW (SW>=0.6)

1002000326595

801600306085

601200255075

501000234567

40800204060

30600183552

20400153045

10200102030

Maximum packet difference (WO3) < 1.0% < 1.5% < 2.0%

Note 1. The quality fluctuation size is not clear, should be GB/T 2007.3 sW determined value, otherwise parts of the number of samples should be large fluctuations in the quality of the sample.

Note 2. The maximum difference between the test packet daily sampling methods can be randomly selected an appropriate amount of the package shall not be less than 5 package, if sampling during the installation package can be inclusive in batches

5 from each pack a bag, take the middle of several packages, but not less than three packages, each package samples were taken from sample preparation, content determination of tungsten trioxide.

5.3 parts of sample volume

Table 2 taking the amount of sample parts, parts for each kind of quality taken should be roughly equal, the relative error does not exceed 20%.

Table 2 Minimum amount of sample parts

Sampling methods increment amount/kg

Per-packet sampling 1

Daobao three shovel Act 5

Daobao reduction of sub-law 50

Skewer Diagonal 0.2

5.4 Sampling Methods

5.4.1 per-packet sampling

In the process of installation packages, each package with a sampling spoon take about 1kg increments. Before sampling, the package must be moved without moving

Move, otherwise prone to segregation of tungsten concentrate bag.

5.4.2 Daobao reduced points system

Table 1 specifies the number of increments randomly selected sample pack, all fell on the flat iron clean, will exceed the 9mm

Crushed particles, reduced by 6.4 to less than 30kg. If the sample preparation for each increment separately, each package of goods prior to crushing all through 5mm

Screen and then shrink to less than 8kg.

5.4.3 Daobao three shovel method

According to the type of batch and quality fluctuate according to the number specified in Table 1 (ie packets) increments randomly selected sample packet-by-packet down to

Smooth and clean iron or concrete floor, making it into a cone, sampling shovel are inserted to the bottom of the circle from three busbars outer cone angle 120 °

Heart, then straight up out of three co-shovel, so take a total of about 5kg increments per pack.

5.4.4 skewer Diagonal

It applies only to a maximum particle size of not more than 4mm tungsten concentrate. Part number of samples specified in Table 1 doubles sample extraction

Bag, open the bag, the sampling stick in diagonal from top-insert until the bottom of the stick will rotate 180 ° sample taken samples, each about 100g, a total of two stick

Take increments of about 200g.

5.4.5

Water samples should be re-balanced sampling can be used along with the quality of the sample, placed in a clean sealed container, being careful not to send the water before measurement

Students change. When larger quantities, long or heavy loading and unloading time, the temperature is high, the goods shall be divided into several parts, each part will be part of the sample prepared

Subsamples determination of moisture.

6.1 sample preparation tools

Sample preparation tools include.

a) a shovel;

b) on the roll crusher;

c) disc grinder;

d) sealed oscillating mill or three mill (with an agate mortar);

e) Second splitter (see specifications GB/T 2007.2);

f) 9mm × 9mm square hole sieve, sieve 5mm, mesh 1.6mm, and 0.18mm mesh sieve 0.075mm sieve;

g) Cross stainless metal sub-model;

h) like shovels and tailgate;

i) Impartial white mixed glass surface like table or mixed sample sets;

j) Sheng injector;

k) brush;

l) Matte wide mouth glass bottle (capacity of about 100mL).

6.2 sample preparation requirements

6.2.1

In the whole sample preparation process should prevent any change in the sample and pollution.

6.2.2

Sample not too wet screening, crushing, shrinking time-sharing, can be pre-dried at 105 °C, to reach suitable for screening and sample preparation

Degree, the weighing before and after drying if necessary, and to calculate pre-dried moisture (wA)% (taking two decimal places).

wA = m-m1 m × 100% (4)

Where.

m --- dried before the total mass of the sample, in kilograms (kg);

m1 --- dried sample of the total mass, in kilograms (kg).

6.2.3 crushed samples

All samples with an appropriate crusher to the required particle size by the total amount (broken according to appropriate conditions

Reducing sample preparation procedures crushing step). Internal crusher must be cleaned before sample preparation and clean. After sample preparation remaining in the crusher inside the sample,

Care must be taken all out.

6.3 sample preparation procedures

And water may be simultaneously or separately as required sample preparation component reference to the following procedure (see Figure 3).

Figure 3 sample preparation flow chart

NOTE. The scheelite concentrate containing calcium chloride can easily absorb moisture, water samples may, without crushing, direct said sample.

6.4 points reduction method

You can use one or more of the following methods and use.

6.4.1 Second splitter and dividing method

Table 3 the appropriate choice of dichotomy, a dichotomy is selected its groove width is approximately equal to the full amount by the sample

Maximum particle size of 2 to 3 times, and subject to checking the accuracy of the test proved to be satisfactory.

All parts within two points must be clean and clean up before use, it shall not be smooth rust inside the trench, using the process to remain smooth groove

Pass unimpeded.

First half of all samples by 2 times, then mix and dividing lines, make sure the sample is uniformly fall into each trench, the sample container filled

Alignment export, rendering the sample scattered outside, which has been divided into two parts of the sample were randomly selected sub-sample 1 as a condensing operation is repeated to not less than the

Minimum size allowance.

Table 3 Sample size and maximum applicable two splitter millimeters

The maximum size is half of the full amount of the sample through the trench width

6.4.2 two open two close quartering

The sample conical pile with a shovel, shovel are required from each of the top vertical cone poured out evenly along the conical tip

Scattered. This conical taper to be piled with a shovel and then successively divided into 2 to 4 reactors, this is a start, then this shovel Synthesis of 2 to 4 Cone alternately

Bunch, this is a, that is, two consecutive two open two together. Each time the process of piles, each shovel shall be poured down from the top of the vertical cone, then the apex of the cone

Tip flattened, since the pressure with a cross plate, divided into four equal portions, either take two pairs of angles aliquots, repeat the operation several times, reduced to less than the size of

Minimum allowance.

6.4.3 reduction of sub-grid method

The sample was placed on a clean flat iron, flat paved rectangular stack, and then partitioned into aliquots flat grid, shrink

Not less than 20 minutes when a large sample grid; no less than 12 time-lapse grid points subsamples; not less than four and dividing grid increments when. With baffle and parts like shovel (see

Figure 4 and Table 4) inserted into the bottom of each cell taken from the same amount of a shovel, a collection of sample points is reduced, a long time when a large number of samples can be divided into several large sample

Equal parts, divided by the above operations and dividing.

4 parts like shovel

Table 4 Sample size, sample thickness and size of parts like shovel

Maximum sample size / mm

Sample layer thickness / mm

Parts like shovel Dimensions/mm abcd material thickness

Shovel volume increment / mL

925 ~ 35,603,560,501 about 125

520 ~ 30,503,050,401 about 75

215 ~ 2540254030 0.5 to about 40

110 ~ 1530153025 0.5 to about 15

0.18 5 ~ 1015101512 0.5 to about 2

6.4.4 cone quartering

The sample is placed on a clean flat iron, into a cone, the cone of each shovel from the top down, so that it evenly along the cone

Scattered sharp, careful not to taper off-center, so repeated at least three times a heap turn to mix well, then flatten the top cone with a cross

Since the pressure plate, divided into four equal portions, either take two pairs of angle equal parts. Repeat several times, reduced to less than the minimum size of the allowance.

6.5 Sample containers and labels

6.5.1

send test water samples (about 200g) shall be charged or frosted glass bottle wide mouth sealed container, attached to the label.

6.5.2

component samples (about 125g) to send test sample should be loaded into the bag, along with the label.

6.5.3

indicate on the label the following.

a) number;

b) name, grade, category, origin;

c) batch or sub-batch;

d) the name or license number;

e) the sampling and sample preparation of personnel;

f) sampling and sample location, date and weather.

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