GB/T 35017-2018Continuous handing equipment - Bulk Solids Chassification, Symbol, Performance and Test methods (English PDF)

3.1 Bulk material

Powdery, granular, blocky material in a loose state.

3.2 Wall shear stress

Shear resistance per unit area produced by sliding a bulk material against the surface of another solid material.

3.3 Wall yielding trajectory

Under different positive pressures, there is a series of equilibrium points on the wall shear stress of the material, which are connected to form a wall yielding trajectory.

3.4 Natural accumulation angle

When the bulk material falls freely and uniformly from a specified height, the maximum slope angle of the conical pile that can be stably maintained is formed (ie, the natural slope) The angle between the surface and the horizontal plane).

3.5 Backward angle

The maximum slope angle alphan formed after the material is continuously discharged through the flat bottom discharge port (as shown in Figure 1).

3.6 Cohesion

Cohesion between particles of bulk material. Cohesion is related to the material properties and the pressures they are subjected to.

3.7 Particle size

The size of the bulk material particles.

3.8 Porosity

The ratio of the pore volume (excluding the closed pore volume) of the material in its natural accumulation state to the natural bulk volume.

3.9 Abrasive

The nature of the solid surface being abraded when the material moves relative to the solid surface it is in contact with.

3.10 Corrosive

A property in which a material chemically reacts with a solid surface in contact to cause the solid material to corrode.

3.11 Hygroscopic

The nature of the moisture (water content) of the material during the stacking or transport process by absorbing moisture from the surrounding air.

3.12 Adhesive

When transported by a continuous conveyor, it tends to adhere to the components of the conveyor with which it is in contact.

3.13 Jointed, entangled and agglomerated

If the material particles are intertwined to form a larger block or web, the material has the characteristics of joining or winding.

Agglomeration refers to the fact that under certain conditions, the material gradually builds up from the initial particles and forms a stable mass.

3.14 Harmful dust, poisonous gas or toxic fumes

A material that produces gases, fumes, and dust that are harmful to the human body, as well as toxic materials that have a toxic effect on the environment or the human body.

3.15 Dust

Particles of bulk material that are small in size and may be suspended in the air.

3.16 Dry weight

The mass of the bulk material sample dried to constant weight within the specified time.

3.17 Wet weight

The mass of the directly sampled bulk material sample.

3.18 Sensitive

The maximum mass required for the balance pointer to deflect from the equilibrium position to the scale 1 division.

4.1 Material density coding system

Material bulk density (loose) rho0 shall comply with the provisions of A.2.8.1 in Appendix A. The density and composition may constitute the classification and coding of the first group of materials.

The materials are classified by density as shown in Table 1.

4.2 Material Granularity Coding System

The granular material classification and coding of bulk materials are shown in Table 2 and Figure 2.

Class A material. refers to dusty materials, which are divided into dusty materials, fine powder materials and coarse powder materials. Such as lake sand or beach sand, dust, dust, Floating dust, finished cement, powdered sugar, rock powder, silt and clay.

Class B material. refers to granular material. Considering the fine size of the material, it is recommended to define it according to the standard sieve hole 3.35mm. Such as coarse grain riverbank sand, A large number of chemicals and processed materials such as salt, sugar and polystyrene.

Class C material. refers to granular material, which is divided into small granular material and granular material. Considering the particle size of the material, it is recommended to sieve according to the standard. The dimensions are defined by 12.5mm, and most are smaller than 6.3mm mesh size. Such as fine gravel (pea), animal feed pellets, iron ore pellets, most valleys Things, beans, nuts, raw materials in factory processing, etc.

Class D material. refers to block material, which is divided into small block material, medium block material, large block material, extra large block material and larger than granularity. 400mm material, considering the material that can be evaluated for the size of the block, is recommended to be defined by the standard mesh size of 12.5mm. Standard sieve hole ruler Inch 75mm, 180mm and 400mm. If the particle size is greater than 400mm, since these materials have special requirements on the equipment, More detailed considerations in terms of length, width, height, quality, and proportion. Such as gravel, coarse gravel, a variety of coal, a variety of ore. "Goose eggs Stones, "rocks", "original ore", etc. should be considered in the form of approximately cubic or spherical shaped blocks.

Class E material. refers to materials with irregular shapes. These materials may be crimped, fibrous or reinforced; measurable thickness cylinders Body or rectangle; or relatively thin and oddly shaped, scaly, wafer-like or plate-like. These materials are oddly shaped and may be joined or entangled in Together, therefore, special requirements should be placed on the conveyor. Such as sawdust, metal fragments or other crumbs, asbestos or rock fragments, trees Skin or garbage, fish and meat or bones, sugar cane, logs, lump coal, metal ore, tobacco leaves, etc.

4.3 Classification of materials

4.3.1 The materials are classified by temperature as shown in Table 3.

4.3.2 Materials are divided into three categories according to humidity.

a) dry material - material containing only structured water;

b) air-dried materials---materials containing structural water and water absorption;

c) Wet materials---materials containing structural water, water absorption and crystal water.

4.3.3 Materials are classified by liquidity as shown in Table 4.

Note: The fluidity of the material can be judged by the flow function.

4.3.4 The materials are classified as wear according to Table 5.

Note: The relative wear of the material can be determined by the wear index, which includes particle hardness, particle shape, bulk density and particle size.

4.3.5 Material classification coding method, classification code is shown in Table 6.

a) Material classification and coding method

Material name [(bulk density range) (average density) (granularity coding) (flow code) (wear code) (other properties or danger Damage coding) (other attributes or hazard coding)].

The contents of each bracket are chosen based on whether the material has the characteristics listed in the brackets.

All characteristics of the material should be considered when selecting the appropriate equipment (see Appendix B).

b) Example of material classification code

Example 1. Dry white lead ore (1.2~1.6) 1.4A0.42536MR

Indicates a bulk density range of 1.2t/m³~1.6t/m³, an average density of 1.4t/m³, a particle size of <=0.425mm, a coarse powdery material, and a conventional flow 2 <FF< 4. Wear index 18~67 Moderately worn, aerated fluidized, dry white lead ore that emits harmful dust, poisonous gas or toxic fumes, see Appendix C.

5.1 General provisions

5.1.1 The error specified in the test method is only to ensure the requirements in the design, manufacture and application of continuous conveying equipment in engineering technology. And set.

5.1.2 Analysis and calculation results The number of digits after the decimal point shall be the same as the number of digits after the decimal point of the allowable error required in the test method.

5.1.3 In daily use, other test methods are not excluded under the premise of ensuring the accuracy of the test results.

5.1.4 The instrumentation, balance, weight and other instruments used in the effective calibration period shall be checked for accuracy before each use, and according to The calibration and calibration of the use of the gauges are regularly corrected.

5.1.5 The samples to be dried shall be dried in an oven at a temperature of 105 ° C ± 5 ° C.

5.1.6 When the sample is placed in an oven at a temperature of 105 ° C ± 5 ° C to dry to constant weight, the interval between two adjacent weighing shall not be less than 3h. When the difference between two adjacent weighing values is not greater than the accuracy required by the test, it is called constant weight value.

5.2 Sampling

5.2.1 For tests that do not have a specified sampling requirement, samples are taken in accordance with this regulation.

5.2.2 Extract representative samples from each batch of material.

5.2.3 The sample taken for the first time shall be not less than 10 parts, and the total amount of the sample shall not be less than 2 times of the test amount (see Table 7).

5.2.4 The initial sample can be taken in the following cases.

a) When conducting routine tests at the transport site, it should be taken within a certain batch gap of the material being transported. When the feeding is uniform and the conveying is positive At all times, it can be extracted over a certain period of time over the entire length of the conveying equipment leading to the pile and the silo.

b) When sampling from a homogeneous stockpile, each batch is 300m³ (or 500m³), and the shortcomings are also discussed in batches. Sample can be taken from the material The pile cones are selected from 10 different points in different parts from top to bottom, but avoiding the extraction of the separated and surface materials.

c) When taking samples from the bagged material, they should be taken from different positions and heights of 10 bags.

5.2.5 After the first sample is mixed uniformly, it is reduced to the required amount of material for the test according to the quadruple method (see Table 7).

5.3 Sampling requirements

5.3.1 Carefully clean the sampling tool and dry the surface of the tool before sampling.

5.3.2 Sampling materials should be piled on cleaned concrete floor or metal platform for mixing and shrinking to avoid mixing other impurities into the sampling. Among the materials.

5.3.3 Sampling materials should not be piled up in places exposed to sunlight or strong winds for mixing and shrinking, so as to avoid the volatilization or dust of the water contained in the materials. Flying and lost.

5.3.4 The sampled materials shall be kept in the original condition before sampling, and shall not be artificially broken, aired or taken other possible changes during the sampling process. Sampling method for material characteristics.

5.4 Sample containers and labels

5.4.1 Samples for moisture (water content) shall be placed in a container with a sealed lid and labeled.

5.4.2 The sample to be inspected shall be placed in the sample bag (or sample tube) with a label attached.

5.4.3 The following contents are indicated on the label.

a) number;

b) name, grade, place of origin;

c) batch (kg);

d) delivery order number (or production lot number);

e) sampling location, date and weather;

f) If necessary, indicate the sampling conditions and process, the raw data of the sample, and the test items and uses.

6.1 Method summary

6.1.1 The sieving method is to sift the sample through a series of standard sieves under certain test conditions, and weigh and retain the materials remaining on each layer of sieve. the quality of. According to the quality of the materials remaining on each layer of the sieve and the total mass of the original sample, the percentage of the gradation of the materials and the cumulative gradation percentage are obtained. Characteristic indicators such as specific particle size and particle composition.

6.1.2 Particle size and particle composition of materials with a particle size greater than 710 µm mesh size are tested by dry screening method, particle size is less than or equal to The particle size and particle composition of the 710 µm material were tested by wet or dry sieve.

6.2 Instruments, tools and reagents

The test equipment shall meet the following requirements.

a) oven (maximum operating temperature.200 ° C, with automatic temperature control and ventilation);

b) platform scale (weighing 10kg, sensing 5g); Pallet balance (weighing 1kg, sensation 0.01g);

c) Standard sieve (standard sieve shall be provided with a sieve bottom sieve seat, and the sieve hole diameter shall comply with the provisions of Table A.1);

d) vibrating shaker;

e) distilled water wash bottle;

f) Porcelain crucible (30mL);

g) dryer (with color-changing silica gel);

h) brush;

i) Ethanol [chemically pure (see GB/T 679)].

6.3 Test procedure

6.3.1 Dry screening method

6.3.1.1 Prepare the sample in the quantities specified in Table 7.

6.3.1.2 Dry the prepared sample in an oven to a constant weight. The dried sample was divided into 2 portions, and the mass of each sample was weighed separately.

6.3.1.3 According to the particle size of the material, select a set of sieves, according to the provisions of A.2.6, determine the minimum mesh standard from the minimum particle size of the material. Screen, the maximum sieve standard sieve is determined by the maximum particle size of the material, and 5 to 6 can be selected according to the demand between the maximum aperture and the minimum aperture. The standard sieve of the intermediate pore size constitutes a set of sieves. The sieves are stacked in the order of the aperture size, and the smallest aperture is placed under the layer, and the sieve bottom is attached. Will give a test Pour into the top sieve, add the sieve cover, and sift through the sieve. Until the throughput per minute is less than 1% of the amount of material remaining on the sieve.

6.3.1.4 The screening of fine materials can be shaken by a vibrating shaker for 30 minutes. After removal, sieve by hand until the throughput per minute is less than the sieve. Up to 1% of the amount of material remaining. It can also be sieved by hand only until the above throughput requirements are met.

6.3.1.5 Weigh the quality of the retained material on each sieve (the coarse material is accurate to 5g and the fine material is accurate to 0.01g).

6.3.2 Wet screening method

6.3.2.1 Take 5L of fine material sample. Dry in an oven to constant weight. The dried sample was taken and sieved through a standard sieve having a pore size of 0.85 mm. When the material under the sieve is less than 3L, the material sample should be sifted. The quality of the retained material on a standard sieve with a weighing aperture of 0.85 mm (fine Indeed to 0.01g).

6.3.2.2 The material after sieving with a standard sieve with a pore size of 0.85 mm is divided into 6 parts (not less than 400 mL each), and each material is weighed. The mass of the sample (accurate to 0.01 g).

6.3.2.3 Fill each of the weighed materials into the specified standard sieves and gently swing the standard sieve to make the specimens evenly on the screen. Spread out.

6.3.2.4 Add the appropriate amount of ethanol to wet the sample. Open the water flow and control the water pressure to 50Pa, so that the sample is completely wetted (no material splashing screen is allowed) Outside), control the water pressure to 200Pa, and carefully rinse the sample until the material in the standard sieve no longer passes through the mesh.

6.3.2.5 Wash the bottle with distilled water, and transfer the remaining material in the standard sieve to the pre-weighed porcelain crucible with a fine water flow. The electric stove slowly evaporates to dryness (no water splashing).

6.3.2.6 Dry the porcelain crucible in an oven to constant weight, take it out, cool it to room temperature in a drying dish, and weigh the porcelain crucible and its memory materials. Quality (accurate to 0.01g).

6.4 Calculation results

6.4.1 The grading percentage is calculated according to equations (1) and (2) (accurate to the second digit after the decimal point).

a) Dry sieve method

Ai-j---the percentage of the grading;

Gi --- the mass of the material remaining on the i-th sieve, in grams (g), calculated according to formula (3);

G0 --- screening test the mass of each sample of the material in grams (g).

b) wet screening

Ai-j---the percentage of the grading;

Gi --- the mass of the material remaining on the i-th sieve, in grams (g), calculated according to formula (3);

Gj --- The mass of the material remaining on the No. j sieve, in grams (g), calculated according to formula (4);

G0 --- screening test the mass of each sample of the material in grams (g).

Gi---the mass of the porcelain crucible containing the material retained on the i-th sieve and the material therein, in grams (g);

Gj---the mass of the porcelain crucible containing the material retained on the No. j sieve and the material therein, in grams (g);

G'i---the mass of porcelain crucible containing the material retained on the i-th sieve, in grams (g);

G'j---The mass of porcelain crucible containing the material retained on the No. j sieve, in grams (g).

6.4.2 The cumulative gradation percentage is calculated according to equations (5) and (6) (accurate to the second digit after the decimal point).

a) Dry sieve method

Ai --- cumulative grading percentage;

Gn---the diameter of the sieve of the i-th sieve is greater than the mass of the material remaining on the sieve of the number, in units of grams (g);

G0 --- screening test the mass of each sample of the material in grams (g).

b) wet screening

Ai---cumulative grading percentage;

Gi---the quality of the material remaining on the i-th sieve and the porcelain crucible, in grams (g);

G'i---the mass of porcelain crucible on the i-th sieve, in grams (g);

G0---Screening test The mass of each sample of the material in grams (g).

6.4.3 Draw the material grading curve according to the grading percentage and the cumulative grading percentage, and determine the typical particle size.

7.1 Test of bulk density