Metode Sampling dan Metode Penentuan Kadar Air dari Bijih Nikel Garnierit

JIS M-8109-1996

Versi Inggris oleh Japanese IndustrialStandard prepared by OMIC

( H . K a n a z a w a = P r i v a t e T r a n s l a t i o n )

August, 1996

JIS M 8109-1996

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Bijih Nikel Garnierite – Metode Sampling, Preparasi Sampel dan Penetuan Kadar Air

Sekop

Spesifikasi metode JIS berikut bertujuan untuk menetukan kadar

rata-rata dan kandungan kelembapan air dari bijih nikel

grnierite,yang selanjutnya disebut “ore”.

(1) Metode Pengambilan Sampel

(2) Metode preparasi sampel untuk tes kelembapan sample dan kadar

sampel

(3) Metode kadar kandungan kelembapan

(4) Metode pengukuran kadar kelembapan dan massa kering dari lot

Keterangan :1. Standar ini, sesuai peraturan, mengacu pada JIS M 81002. Metode yang relevan dengan standar ini ditetapkan dalam standar berikut :

JIS M 8100, JIS M 8126, JIS Z 8401, JIS Z 8801

Standar yang berlaku :

JIS M 8100 – Aturan Umum untuk Metode Sampling Material Ruah dari

Produk Tambang

JIS M 8126 – Metode Penentuan Nikel pada Bijih

JIS M 8129 – Metode Penentuan Kobalt pada Bijih

JIS Z 8401 – Aturan Untuk Pembulatan Nilai Numerik

JIS Z 8801 – Saringan Untuk Keperluan Pengujian

JIS M 8109-1996

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DEFINISI ISTILAH

Definisi beberapa istilah yang digunakan dalam standar ini adalah sebagai berikut:

(1) Lot

A quantity of ore agreed upon between the parties concerned

for the purpose of determining the average of the ore. The

quantity of ore constituting a lot is called the size of the

lot.

Banyaknya jumlah bijih yang disepakati antara pihak-pihak yang

bersangkutan untuk tujuan menentukan rata-rata bijih. Jumlah

bijih yang terdapat di lot disebut ukuran dari lot.

(2) Sub-lot

The average of the ore consisting of part of lot as divided,

when required, into appropriate quantities.

Rata-rata dari bijih terdiri dari bagian dari lot yang

terbagi, bila diperlukan, dalam jumlah yang sesuai.

(3) Increment

A quantities of ore taken by a sampling device, as a rule in a

single motion, from lot or sub-lot. A unit quantity of ore

taken from a sample by the increment reducing method is also

call an increment. The weight of a increment is called the

size of the increment.

Sebuah jumlah bijih yang diambil oleh perangkat sampling,

sebagai aturan dalam gerakan tunggal, dari lot atau sub-lot.

Sebuah unit kuantitas bijih yang diambil dari sampel dengan

kenaikan mengurangi metode ini juga panggilan kenaikan. Berat

selisih ini disebut ukuran selisih tersebut.

(4) Partial Sample

The sample collecting on some increments, whet required, after

JIS M 8109-1996

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preparation of each increment is taken is called the partial

sample.

Teknik pengambilan sampel pada beberapa kenaikan, mengasah

diperlukan, setelah persiapan setiap kenaikan diambil disebut

sampel parsial.

(5) Belt Sampling

When the lot is being moved by a belt conveyor the increment

shall be taken from a surface of belt and from the

discharged outlet of conveyor.

Ketika banyak sedang dipindahkan oleh conveyor belt kenaikan

tersebut harus diambil dari permukaan sabuk dan dari outlet

habis conveyor.

(6) Truck Sampling

W h e n t h e lot is being handled by truck or wagon.

Increment shall be taken from inside of truck or wagon.

Ketika banyak sedang ditangani oleh truk atau gerobak.

Kenaikan harus diambil dari dalam truk atau gerobak.

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(7) Hatch Sampling

Increment shall be taken from inside handling implements when

the let is being handled by such implements as grabs, buckets,

sling tees, or freshly exposed surface of the ore in a

lighter.

Kenaikan harus diambil dari dalam mengimplementasikan

penanganan ketika mari sedang ditangani oleh alat seperti

diperebutkan, ember, tee sling, atau baru terkena permukaan

bijih dalam ringan.

(8) Composition Sample

The general term of samples taken from lot or sub-lot for the

purpose of determining the average grade of the composition.

A sample taken from a prepared sample of a composition

analysis sample.

Istilah umum sampel yang diambil dari banyak atau sub-banyak

untuk tujuan menentukan nilai rata-rata komposisi. Sampel

diambil dari sampel disiapkan sampel analisis komposisi.

(9) Moisture Sample

A general term of samples taken from a lot or sub-lot for the

purpose of decerminir4 the average moisture content. A

sample taken for determining moisture content,

prepared by crashing and reduction, and

subject to measurement is called a moisture

measurement sample.

Sebuah istilah umum sampel yang diambil dari banyak atau sub-

banyak untuk tujuan decerminir4 kadar air rata-rata. Sampel

diambil untuk menentukan kadar air, disiapkan oleh menabrak

dan pengurangan, dan tunduk pada pengukuran disebut sampel

pengukuran kelembaban.

(10) Split-Used Sample

The split-use a sample signifies that the sample is divided

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into parts and employed for the measurement

of two or more characteristics.

Perpecahan-menggunakan sampel menandakan bahwa sampel dibagi

menjadi beberapa bagian dan digunakan untuk pengukuran dua

atau lebih karakteristik.

(11) Multiple-Used Sample

The multiple-use a sample signifies that the entire sample is

employed in the determination of one characteristic, and

thereafter, the same sample in the entirety or part is

employed for the determination of another characteristic.

The multi-menggunakan sampel menandakan bahwa seluruh sampel

yang digunakan dalam penentuan satu karakteristik, dan setelah

itu, sampel yang sama di keseluruhan atau sebagian digunakan

untuk penentuan karakteristik lain.

(12) Maximum Particle Size

The size of the mesh of a sieve corresponding to a sieve

having a 5% oversize residual factor for the sample. The

sieve of this standard shall, as a rule, conform with JIS Z

8801.

Ukuran mesh saringan sesuai dengan ayakan dengan faktor sisa

kebesaran 5% untuk sampel. Saringan dari standar ini harus,

sebagai suatu peraturan, sesuai dengan JIS Z 8801.

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A SYMBOL

This standard is employed following the symbol.

Standar ini digunakan mengikuti simbol

N : Size of the lot or lot weightN : Ukuran lot atau berat lot

n : Number of the taken sample from one lotn : Jumlah yang diambil sampel dari satu lot𝜎 : Precision indicated by the standard deviation

Σ : Presisi diindikasikan dengan standar deviasi𝜎𝑏 : Dispersion among primary sampling units or among strata

expressed by the standard deviation

𝜎𝑤 :Dispersion among the increments in the primary sampling units

or in the stratum expressed by the standard deviation𝜎𝑠 : Sampling precision expressed by the standard deviation𝜎𝑝 : Preparation precision expressed by the standard deviation

: Including preparation and analysis or measurement precision

expressed by the standard deviation

: Including sampling, preparation, analysis or measurement

precision expressed by the standard deviation (Composite

precision)

4. GENERAL ITEMS

4.1 A Summary of Samp li n g an d Sa mpl e Pr ep aratio n

A Summary of sampling and sample preparation are as follows (Fig.

1)

(1) The size of lot shall be decided, thereafter meet the

size of lot number of sub-lot shall be decided.

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(2) The meet of maximum particle size and the quality

variation of characteristic shall be decided on method

of sampling and number of increment.

(3) Be taken increment, thereafter increments be collected

and co re partial sample.

(4) This partial sample are crushed, reduced then shall be

made composition analysis sample and moisture

measurement sample.

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Fig. 1 Summary of Sampling and Sample Preparation (An Example)

4.2 The Handling of Samples

Throughout the handling, preparation, and measurement of

the sample, attention shall be paid to prevent change in

quality or loss of the sample and all

apparatus shall be kept scrupulously clean to

prevent foreign substances mixing with the sample.

(1) Sample container:

Sample Container shall be as follow:

a) Container to be employed for the purpose of

transporting or storing various sample shall be

hold the entire quantity of the sample, be clean and

strong, and shall be capable of being closed or

sealed.

b) In particular, it is necessary that the container

for moisture samples shall be airtight and made of

non-hygroscopic material, and also the interior of

the container shall not be corroded.

Remark: straw and jute bags are not suitable as

containers for moisture sample.

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(2) Packing and marking of prepared composition analysis sample

Prepared samples shall be sealed in container which

shall be coated with aluminum foil or Poly-ethylene bag

and these shall be sealed in paper bag and forwarded,

distributed, or stored. The package shal1, as a rule,

be the following items.

a) Name of the Commodity (Brand)

b) Name of the lot (Ship's name) and size

c) Number of sub-lot

d) Date of sampling and preparation

e) Name of factory of sampling and preparation

f) Name of in charge of sample preparation

g) Other necessary information

(3) Storing of samples

Storing of the samples shall be as follows:

(a) Prepared sample in accordance with (2) shall be

stored as a rule, for 6 months

(b) When storing samples, to prevent any change in quality,

sample shall be sealed in a container and attention

paid to the place of stage to exclude any effects of

temperature, direct sunlight and moisture

(4) Forwarding of sample

Sample other than the composition sample shall not, as a

rule, be forwarded, provided that, when forwarding can

not be avoided, the forwarding method shall be decided by

consultation between the parties concerned.

4.3 Determination of Average Quality

For the nickel content, analysis shall be performed on each

sub-lot accordance with JIS M 8126, and mean valve of this

analysis shall be taken as the average quality of the sub-

lot. The average quality of the lot is determined by

calculating the weighted average value

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of the sub-lot down to three decimal places and rounding off

the result to two decimal places. For moisture content, the

value obtained from the method specified in 5. Method of

determination moisture content shall be taken as the value

for the lot.

4.4 Rounding off of Numerical Value

Numerical value shall be rounded off is accordance with JIS Z.

8401.

4.5 Other Item

Other item shall be performed as follows:

(1) The necessary item shall be not specified on this standard.

This item shall be decided by consultation between the

parties concerted.

(2) In case it is considered difficult to apply a part of

specification of this standard. The method based on the

agreement between parties concerned may be used in

place of this specification.

(3) Check experiment of the sampling method shall, as a rule,

be performed according to Appendixes V, VI and VII.

Examination shall be made to determined whether the

specified accuracy is being maintained with change in

handling process of lot, or whether there is any bias

of contents.

5. KIND OF SAMPLING

5.1 The Size of lot and Sub-lot

As a rule, the size of one lot shall be the quantity of

one shipment of ore that is contracted, although maximum

size of sub-lot shall be within 5,000 tons.

Characteristics

Size of lot(t)

30,000 More45,000 Less

20,000 More30,000 Less

10,000 More20,000 Less 10,000 Less

Ni-Contents % 0.020 0.024 0.032 0.040

H2O Contents % 0.48 0.58 0.76 0.94

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5.2 Characteristics and Accuracy

5.2.1 Characteristics

The characteristics having accuracy specified shall be, as a

rule, the nickel and moisture contents.

5.2.2 Overall accuracy

The value of overall accuracy shall be expressed Table 1.

Table 1 Overall Accuracy (2 )

Characteristics

Size of lot(t)

30,000 More45,000 Less

20,000 More30,000 Less

10,000 More20,000 Less 10,000 Less

Ni-Contents % 0.025 0.030 0.040 0.050

H2O Contents % 0.5 0.6 0.8 1.0

5.2.3 Sampling accuracy

The value of sampling accuracy shall be expressed Table 2.

Table 2 Sampling Accuracy (2 )

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5.3 Classification of the Magnitude Variation

The magnitude of the grade variation of ore shall be classified

as shown in Table 3 for nickel content and shown in Table 4

for moisture content.

Table 3 Classification of Magnitude of Variation (Nickel Contents)

Unit: %

Classification �

�

��𝑏Large 0.25 or More 0.15 or More

Medium 0.15 More 0.25 Less 0.05 More 0.15 Less

Small 0.15 Less 0.05 Less

Table 4 Classification of Magnitude of Valuation (Moisture Contents)

Unit: %

Classification �

�

��𝑏Large 5 or More 3 or More

Medium 3 More 5 Less 1 More 3 Less

Small 3 Less 1 Less

Remarks: 1. The magnitude of grade variation shall be

determined according to Appendix Ⅲ and Ⅳ of JIS M

8100.

2. When the magnitude of ore is unknown, as a rule,

the subject shall be treated as having a “large”

grade variation until identified.

5.4 Timing of Execution of Sampling

The time for taking increments shall be as follow:

(1) When the lot is being delivered and/or moved

(2) In a period immediately before or after weighing the

lot as possible

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5.5 Kind of Sampling

The kind of sampling shall be the following three.

(1) Belt sampling

(2) Truck sampling

(3) Hatch sampling

5.6 Increment

5.6.1 Size of increment

The size of increment shall be the mass specified in Table

5, according to the maximum particle size of the increment.

Remarks: When sampling, the increment of approximately

uniform size shall he taken. Approximately uniform

signifies that the dispersion of the increment size,

aim expressed. As a coefficient of variation, is less

than 20%.

5.6.2 Increment sampling devices

(1) Increment sampling scoop

As a rule, increment-sampling scoops of the dimensions

specified in Table 5 shall be used, according to the

maximum particle size of the lot.

(2)

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Table 5 Scoop for Increment Taking & Sample Reduction

Scoop number

Max. Particle Size

Dimensionsb/c

Capacity

(Approximately)a b c d e f g thick

150 150 450 190 450 380 170

Suitable

Suitable

3 0.42 35,000

125 125 380 160 380 320 150 3 0.42 21,000

100 100 300 130 300 260 120 3 0.43 11,000

70 71 200 100 200 170 80 2 0.50 3,700

50 50 150 75 150 130 65 2 0.50 1,600

40 40 110 65 110 95 50 2 0.59 730

30 31.5 90 50 90 80 40 2 0.56 380

20 22.4 80 45 80 70 35 2 0.56 270

15 16 70 40 70 60 30 2 0.57 180

10 10 60 35 60 50 25 1 0.58 120

5 5 50 30 50 40 20 1 0.60 70

3 2.8 40 25 40 30 15 0.5 0.62 35

1 1 30 20 30 25 12 0.5 0.67 16

0.25D 0.25 15 10 15 12 8 0.3 0.67 2

Remark: 1. When use these scoop for the increment reduction,

use the scoop without triangular edge (e=0) and

append D at the right side of scoop number.

2. The scoop number 0.25D shall be used only for

reduction of increment.

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Mechanical Sampling devices

(a) Installation of equipment

The mechanical sampler shall be installed at a point where the entire quantity of a lot shall pass when lot is moved.

Remark: For example, the sampler shall be installed at the discharged outlet of the main belt conveyor and there is a sampler of cutter type.

(b) Sampler

The opening of sampler shall be of a dimensional size (as a rule, 3 or more time the maximum particle size of a lot) capable of easily taking particles of the maximum particle size of a lot. Furthermore, the sampler shall be of a structure preventing the overflowing of the sample from container, and clogging of the chute.

(c) Sampling interval

It is desirable chat the sampler shall be capable of varying the sample interval.

(d) Safety

Sufficient cares shall be taken on the safety of workers in designing and installing the mechanical sampling apparatus.

(e) Maintenance and monitoring

The mechanical sampler apparatus should preferably be so constructed that the maintenance and cleaning are easy throughout all the system such as sampler, conveyor, hopper, crusher, etc. and its material are corrosion proof.

Further, each function should preferably he easily monitored during operation.

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(f) Check of bias

After installing the mechanical sampling apparatus, it is necessary for the mechanical sampling to confirm as soon as possible that the sample taken by this apparatus are free from bias.

Remark: Check experiment of the sampling shall, as a rule, be performed according to the Appendix 6 of JIS M8100.

(g) Check of overall precision

The mechanical sampling apparatus should preferably be so constructed that the check experiment of overall precision can be carried out easily.

Remark: As a rule, Appendix 5 of JIS M 8100

(3) Other sampling devices

(a) The increment shall be free from bias,

(b) The capacity shall be not less than that of Table 5.

5.6.3 Number of taking increment

The minimum required number of increments taken from lot

shall be specified according to kind of sampling 5.9.2,

5.10.2 and 5.11.2.

5.6.4 Method of taking increment

Use the sampling devices specified in 5.6.2.

(1) Take the increment at random by one working action so that the size of increment shall become nearly uniform. however when it is difficult to take by one working action, the increment may be taken by several action from one place selected at random and these samples may be combined to constitute one increment.

(2) Take the increment, as a rule, from the lot during handling.

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(3) Don’t change the sampling interval during sampling work

of cue lot.

Even when the taking specified number of increments has

been finished, the increment shall be continuously taken

at the specified interval without discontinuing the

taking of increment as long as the material handling of

lot is carried out continuously.

5.7 Collection of Increment

Every quantity (about 100-500t) shall be collected each

increment thereafter it become a partially sample and

moisture and composition sample shall be prepared from

these.

5.8 Split-use and Multiple-use of Sample

The sample cm be used in split and, or' multiple for

particle sample, for moisture content and for constituent, as

required, when the sample is used in split for these

purpose, the sample meeting the characteristics of largest

number of increment shall be used, and when sample use for

multiple be satisfied with follows.

(1) After measuring of moisture sample is flied away easily. There are apparatus of prevention of flied away at crushing and reduction.

(2) By check of experiment of sample, moisture and nickel content is not changed is confirmed.

5.9 Belt Sampling

5.9.1 Taking place of increment

When the lot is moved by a belt conveyor, the increment shall

be taken from the specified place on the belt or its chute.

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5.9.2 Number of Increment

The minimum required number of increments taken from one

lot shall be determined in accordance with Table 6.

Table 6 Minimum Required Number of Increment

Size of Lot(t)

Variation

Large Medium Small

10,000 Less 225 100 40

10,000 More 20,000 Less 360 160 65

20,000 More 30,000 Less 670 300 115

30,000 More 45,000 Less 900 400 160

5.9.3 Taking method of increment

The taking method of increment shall be as follows:

(1) Carry out the systematic sampling by the random start

The sampling interval of increment shall be determined by dividing the size of lot N (for example, tonnage

(t)) by number of increments n to be taken by round off the figures below decimal point.

(2) When taking increment after the stopping belt conveyor, take the increment of quantity of not less than the specified size at the specified place of conveyor. In this case, cake the whole quantity along the moving direction of belt ranging over the full flow width of belt, which is not less than three times the maximum particle size as one increment.

Remark: The full flow width signifies a cross section possessing a certain length (width) to, and approximately at right able to, the direction of movement of conveyor, or the direction of full at the chute when ore is being moved by belt conveyor.

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(3) When increments are taken from the belt conveyor is operating, a quantity equal or larger than the specified increment shall be taken covering the full flow width at chute of conveyor by sampler.

Remark: When taking in the full flow width is impossible, after confirming that it is free from bias, selected a place at random is the full flow width at every tine when the increment be taken on the belt conveyor or its

chute and take the increment by the specified sampler.

5.10 Truck sampling

5.10.1 Place take of increment

Place take the increment from the truck and freight car

under a lot handling

5.10.2 The Number of drawn truck on minimum required increment

The first stage, the number of truck shal1 be drawn from Table 7. The second stage, two increments shall be taken from each drawn truck.

Table 7 Minimum Required Number of Truck

Size of Lot(t)

Between

Large Medium Small

Within(𝜎𝑤 ) Within(𝜎𝑤 ) Within(𝜎𝑤 )L M S L M S L M S

10,000 Less 215 150 120 140 75 45 115 55 25

10,000 More 20,000 Less 340 240 195 220 120 75 185 85 35

20,000 More 30,000 Less 630 445 355 410 225 135 340 155 65

30,000 More 45,000 Less 850 600 480 550 300 180 460 210 85

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5.10.3 Method of taking increments

The method of taking increments shall be as follows:

(1) The truck from which increments shall be taken shall be selected as the first stage of two-stage sampling. The method of selection shall be systematic sampling.

(2) The interval of extracted trucks for raking increments shall be determined by dividing the size of lot with number of required truck and to be taken by round off figure below decimal point.

(3) For taking increments from inside of truck, the places of sampling shall be selected at random and the increments shall be taken from surface of the cargo freshly exposed by handling.When the increment is taken from surface of the cargo when it is loaded on the truck, it shall be confirmed by check experiments that the increment is free from bias.

5.11 Hatch Sampling

5.11.1 Pace for taking increments

Increments shall be taken from inside handling implements when the lot is being handled by such implements as grabs, buckets, sling net etc, or from a freshly exposed surface by handling of the cargo in a lighter.Instead of taking increment from inside the handling. implements sampling may be made after transferring to the ore of the implement to a flat place. Provided that, in this case, it shall be ascertained by check experiments that the sample is free from bias.

5.11.2 Number of increment taking

The minimum required number of increments to be taken from

one lot shall be as specified in Table 6. Provided that,

when the number of increments taken from a single handling

implement is two in 5.10.2.

In case this, replace between number of truck and number of

grab and from extracted grab shall be taken two increments.

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5.11.3 Method of taking increments

Shall be as follows:

(1) Carried out the systematic sampling by random start

The sampling interval of increments shall be determined

by dividing the size of lot with the number of required

increments and to he taken by round off the figure

below decimal point.

(2) In case of taking increment from inside of hatch of freshly surface of cargo by handling, the place of taking increments shall be determined by at random.

6. METHOD OF SAMPLE PREPARATION

6.1 The Sample Preparation

The sample preparation are as follows:

(1) Samples shall prepared by crushing and reducing partial sample as they pie

(2) For composition samples, when necessary further drying shall be performed

(3) For moisture content samples shall he prepared by further dividing partial sample into small sample quantities, and subjecting to increment reduction par sample taken from each of these small quantities.

(4) When the composition sample and moisture sample are subjected to split or multiple uses, the preparation of the moisture sample shall conform to (3).

(5) The reduction of sample shall be applied proper reduction method in accordance with in 6.5.6.

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(6) Care shall be taken so that during sample preparation a part of sample cannot be dispersed and dusts from surroundings and other foreign material cannot be mixed.

6.2 Accurac y of preparation

Accuracy of preparation is as follows in Table 8.

Table 8 Accuracy of Preparation ( )Characteristics

Size of lot(t)

30,000 More45,000 Less

20,000 More30,000 Less

10,000 More20,000 Less 10,000 Less

Ni-Content % 0.011 0.013 0.017 0.021

H2O Contents % 0.11 0.16 0.22 0.32

Remarks: In regards to moisture, the accuracy of approximately

95%, probability is expressed by double the

reduction analysis accuracy

6.3 Preliminary Drying Composition Sample

When taken samples are more wet and to screen, crush and

divide are very difficult. Samples may be solar-dried or

dried in

an oven at temperature 100℃ or less to an extert will not impede

the use of the crusher or reducing devices.

6.4 Crushing of sample

Crush the whole quantity of sample by an appropriate

crusher up to the particle size that allows the whole

quantity of sample to pass through the specified sieve.

(1) Selection of crusher

Select the crusher having the type and capacity suited

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for the particle size of sample to be ground, particle size of sample after crashing and physical properties (Note) of sample.

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Note The physical properties are defined as hardness,

rigidity, specific gravity, water content,

stickiness, and others.

(2) Cleaning

The inside of crusher shall be cleaned before the

sample is supplied.

(3) Preliminary cleaning

When crushing the different sample from the sample

which has been crushed at the last time, it should be

preferable to pass as appropriate quantity of

particulate materials taken from the lot previously

through.

(4) Taking of sample

Take care to take out the whole sample remaining in the

crusher. (5) Prevention of deterioration

Take care to avoid the determination of sample due to

the type of crusher or the heat generated by the long

hours continuous operation and the like.

6.5 Reduction of Sample

6.5.1 Classification of redaction method

(1) The reduction method shall be classified in to the following

4 methods shall be applied one method or this method in parallel.(a) Increment reduction method

(b) Method of riffle sampler

(c) Method of toting and quartering

(d) method using a reducer

(2) Reduction shall be performed on sample hiving at passage particle size of 22.4 mm or less.

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(3) Standard for reduction shall comply with 6.5.6.

(4) The apparatus using for reduction shall be cleaned enough, when reduction of sample which is instead before reduction one, other samples taken from lot shall be had ready beforehand shall be used for cleaning.

(5) During reduction of sample take care to avoid the deterioration, scattering and foreign material of sample.

6.5.2 increment reduction method

(1) The size of shovel for the increment reduction and the thickness of the spread sample shall be as given in Table 9 according to the particle size of the sample.

Remark The pipe, etc can be used instead of increment

reduction scoop. However, the inner diameter of

pipe, according to the particle size of sample,

in shown Table

5a.

Samples shall be spread fit for pipe reading at

bottom and taken sample; no fallen

Table 9 Particle Size of Sample and Scoop Size for Increment Reduction

Particle Size for Total

Passage of Sample

Number of ScoopThickness of Sample

Spread out()

22.4 Less 20D 35~45

16.0 Less 15D 30~40

10.0 Less 10D 25~35

5.00 Less 5D 20~30

2.80 Less 3D 15~30

1.00 Less 1D 10~20

250 𝜇 Less 0.25D 5~10

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(2) The number of increments per sub-lot shall be 100 or more. provided that, when the total passage particle size of the sample is 10 mm or less and the sample is sufficiently dried to be thoroughly mixed, the number of increments per sub-lot shall be 20 or more.

(3) When manually performing increment reduction of small samples, Attached Fig. I shall followed.

(stage 1) The sample shall be spread uniform on a

plain place in a rectangular with shown

Table 9.

(stage 2) The 2.ength shall he divided 4 and width 5.

(stage 3) one increment shall be taken from each

division, (in each division place be

selected at random). Total 20 increment

shall be taken which is be after reduction

sample. When taking samples, the scoop

shall be put into bottom of sample.

Remarks 1. When a quantity of samples larger than the

quantity of samples taken by the above

method is required after reduction, the

size of the increments shall be made

larger, or the number of increments shall

be increased. When increasing the number of

increments, the

number of divisions shall be increased or

the number of increments taken

from a single

division shall be increased, but, the

number of increments taken from each

division shall be uniform.

2. When performing increment reduction, it is

desirable that the increments be taken with

the use of a backing plate.

6.5.3 Method using riffle sampler

JIS M 8109-1996

27

(1) According to the particle size of the sample, ate rule, a riffle sampler shown in Table 10 shall be used.

JIS M 8109-1996

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Table 10 Particle Size and Types of Riffle Samplers

Passage Particular Size() Riffle

SamplerSlot Width

()Over Under

16.0 22.4 50 50±1

10.0 16.0 30 30±1

5.00 10.0 20 20±1

2.80 5.00 10 10±0.5

2.80 6 6±0.5

(2) The riffle sampler shall be as follows:

(a) An example of the structure and dimensions of

various types of riffle samplers is shown in

Attached Fig. 2.

(b) The upright angle (e) included between the two

sloping surfaces shall be 60 degrees or less.

(c) The slots shall be of an even number and, as a rule,

16 or more. Provided that the number of slots of Nos.

50 and 30 types shall be 12 or more.

(d) The sample receivers shall fit perfectly the

outlets of the riffle sampler, and shall be of a

structure preventing scattering of finely powdered

ore.

(e) The inner surfaces of the riffle sampler shall be

smooth, and samplers with corroded surfaces shall

not be used.

(3) The samples shall be mixed, put into the container, and dropped uniformly down the main body of the sampler to halve the samples. One of the halves shall be selected at random to be the reduced sample.

Remark: When using a riffle sampler, care must be taken

JIS M 8109-1996

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to prevent clogging of the slots.

JIS M 8109-1996

30

(4) Me standards for reduction shall be as specified in 6.5.6.

6.5.4 Method of corning and quartering

According to JIS M 8100 6.5.4.

6.5.5 Method using of reducer

It shall be ascertained that the reducer has adequate

accuracy and in free from bias. Standard of reduction shall

be as specified in 6.5.6.

Remark: The reducer shall be cleaned enough, when

reduction of sample which is instead before

reduction one, other samples taken from lot shall

be had ready beforehand shall be used for cleaning.

6.5.6 Reduction standard

The relationship between the particle size for total

passage of sample and the weight of the sample after

reduction shall be, as a rule, as given in Table 11.

Provided that, in the case of increment reduction, 6.5.2

shall be follows.

Table 11 Particle Size and Reduction Standard

Passage ParticularSize

Weight of Sample after Reduction (kg)

22.4 Under 140 Min.

16.0 Under 70 Min.

10.0 Under 35 Min.

5.00 Under 8 Min.

2.80 Under 2 Min.

1.00 Under 0.5 Min.

420 𝜇 Under 0.1 Min.

250 𝜇 Under 0.05 Min.

JIS M 8109-1996

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Remarks: 1. This table be shown bulk density of sample is one.

JIS M 8109-1996

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6.6 Preparation of Samples (for Composition)

The preparation of samples (for composition) shall be as follows:

(1) Partial samples shall be crushed finely to 150 or less and mixed well. From this the required number of 100g or

more in weight samples shall be prepared, employing

the increment reduction method or a reducer.

(2) The above sample, placed in a polyethylene bag and

sealed and further in a specified paper bag and sealed,

shall be taken as prepared sample.

(3) As a rule, composition sample shall be prepared four

samples for shipper; buyer, umpire and reserve.

6.7 Preparation of Moisture Measurement Sample

The moisture measurement sample shall be prepared as follows:

(1) As a rule, 1 moisture measurement sample of 1 to 5 kg

shall be prepared by the increment reduction method

from partial samples for moisture content made by

further subdividing the sub-lot and crushing separately

to 22.4 mm or less.

(2) Small samples for moisture content shall, as a rule, be

reduced by the increment reduction method. In this case

the number of increments shall comply with 6.3.2; and,

if the specified quantity for a moisture measurement

sample is satisfied, a scoop smaller by cue step

compared to the grain size shown in. Table 5 may be

used for the increment size.

Remarks: Moisture measurement sample prepared by a

reduction method employing a scoop 1 step

smaller shall not he multiple-used as

composition samples.

JIS M 8109-1996

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7. METHOD OF DETERMINATION OF MOISTURE CONTENT

7.1 Summary

The moisture measurement sample prepared according to 6.7

is dried at a specified temperature until it becomes

constant weight and the decrease in weight is determined,

then the percentage moisture content to the

sample weight is calculated.

7.2 Sample

A moisture measurement sample prepared according to 6.7 is

to be employed.

7 . 3 Apparatus

The apparatus shall be as follows:

(1) Drying container:

The container shall be such that the thickness of the

sample should be 30 mm of less.

(2) Dry:

The dryer shall be capable of maintaining the drying

temperature of the sample at 105±5℃.

(3) Scales:

The scales shall have a reciprocal sensitivity of

1 five-thousandth or less of the sample weight.

7.4 Operation

Operation shall conform to the following procedure.

JIS M 8109-1996

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7.6 Decisive Value

As to the moisture content of a sub-lot, to two, the

weighted mean value according to the number of increments of

the moisture content of the small samples for moisture which

were determined in 7.5 should be calculated and rounded off

to two decimal places.

The weighted mean value according to the size of the sub-

lots, rounded off to one decimal place, of the moisture

content (%) of the sub-lots shall be the decisive value of

the moisture content of the lot.

8. METHOD OF DETERMINING THE DRY MASS

The dry mass of a sub-lot shall be calculated from the

following formula.

Dry mass of sub~lot t= Weight of sub~lot tMoisture content of sub~lot determined by 7.6 %× 1 − 100The decisive value of the dry mass of a lot is determined

by, adding together the dry masses of the sub-lots of 1 lot

and, as a rule, rounding off to four significant figures.

JIS M 8109-1996

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Type

No. of

slots

No. 50 No. 30 No. 20 No. 10 No. 6

12 12 16 16 16

Symbol

A 50±1() 30±1() 20±1() 10±0.5() 6±0.5()B 630 380 346 171 112

C 250 170 105 55 40

D 500 340 210 110 80

E 300 200 135 75 60

F 50 30 30 20 20

G 340 340 210 110 80

H 200 140 85 45 30

I 640 390 360 184 120

J 220 220 140 65 55

K 220 220 140 65 55

L 340 300 210 110 80

M 250 170 105 55 40

N 75 55 35 20 15

O 340 300 210 110 80

P 630 380 346 171 112

Q 400 300 200 120 80

R 265 200 135 70 45

S 200 150 105 50 35

Remarks: 1. No. 50 and No. 30 shall have 12 or more slots

and No. 20, No. 10 and No. 6, not less than 16.

A shows the specified dimensions of the slots.

2. The dimensions from B to S are shown only as examples.

JIS M 8109-1996

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Attached Fig.1. Increment Reduction Method

(When Performed Manually)

(Example of dividing by 20)

The crushed large sample is

spread out rectangular to the

thickness of Table 10 in

this text.

The scoop is thrust into the

bottom and a scoopful of ore

is taken from a division at

random from the 20 equal

parts. These are collected

to form the sample.

JIS M 8109-1996

37

This is divided into 20 equal

parts. For example, into 5

equal parts on the long side and

4 equal parts on the short side.

③ Method of sampling using a

backing plate.