(two) sampling method
1, sampling conditions
(1) The smaller the particle size, the easier it is to collect representative samples. Therefore, in the case of meeting the process requirements, the material should be crushed to the minimum particle size before taking the sample.
(2) are unevenly distributed in the grain size and metal content of the material throughout the material, samples should be increased.
(3) There are only a few large pieces in the material. If the sample volume is calculated according to the sampling weight formula, the sample volume will be too large. For this reason, a small number of large pieces can be broken before sampling.
(4) The flow slurry should be selected for sampling where the slurry flow has a certain height difference and the flow rate is not large.
(5) The moving material should be sampled during the rotation process.
(6) Industrial tests should select safe and reliable sampling locations and methods according to the production site conditions.
2. Static sampling of loose bulk material.
Such materials are generally piled into ore piles or installed in mine cars (or mines). The sampling method is:
(1) Sampling of the heap
1) Generally, the dotted line method is used to draw a series of horizontal lines parallel to the bottom of the pile at a distance of 0.5 m on the surface of the entire pile (the distance between the bottom line and the bottom of the pile is 0.25 m) Then, a production point is arranged 0.5 to 2 meters apart on the line. Sampling vertical iron spade dug pit depth of 0.5 m in the surface of the pile of ore mining capacity in the bottom of the pit, the weight of a sample taken at each point (or take several shovel) should be proportional to each pit points to the bottom of the vertical stack The sample taken from each point is a sample of the material.
2) Sampling on the ore heap with large changes in ore physical and chemical properties, the sampling well should be excavated from the heap. The well should be dug directly from the top of the pile. The number of wells and their arrangement should be determined by the degree of metal content in the ore and the purpose of sampling. The difference is determined on a case-by-case basis.
When digging a well, each layer (1~2 meters) must be piled into a small pile. After digging, the piles are hard to dry, and then each pile is sampled by the extraction method. The well sample. When the samples of each well are integrated together, the weight of the sample to be mixed shall be determined proportionally according to the depth of each well.
When the metal content of the block and the powder ore is very uneven, the powder ore should be sieved out before the extraction, and the weight percentage should be obtained. Then, the sample is taken from the lump ore and the fine ore, and they are obtained according to the method. The ratios are combined into one sample.
(2) Sampling in the mine car
1) Problems to be noted in sampling in mine cars
1 When the material contains more fine powder, the segregation falls to the edge of the mine car due to segregation during loading, and the middle is mostly fine powder. In the case of still, the lump ore and the powder ore are different in nature, so sampling More points should be;
2 When the box is shaken and vibrated during operation, the heavy minerals gradually sink. If the transportation distance is very long, and the difference in the specific gravity between the minerals in the material is large, the stratification phenomenon is easy to occur. law;
3 car box size, when the car is large, the sampling point should be more;
4 The number of carts, if the total number of carts occupied by the ore to be sampled is large, the sampling points per car can be correspondingly less.
2) Surface extraction method
Several production points can be arranged above the mine car, and its arrangement is shown in Figure 3.
At the sampling point, it can be manually taken, or a small pit with a depth of 0.25~0.5 meters can be used as a sample, and the samples of each sampling point are mixed and the sample is taken. [next]
3) Stratified sampling method
For the ore distributed and uneven in the mine car, the stratified sampling method is applied for sampling. This method is generally carried out when loading or unloading the vehicle. First, the surface of the 1/6 height of the car is removed, and then the surface is taken. Then, the upper ore layer of the 1/2 height of the rut is removed, and it is also taken by the surface picking method. Generally, it is divided into two layers, and the sample taken by the two layers at each point is mixed as the sample of the mine car.
3. Sampling of static loose powder material
This kind of material is generally taken by the probe method. First, the fine powder material in the mine or the mine car is drawn into several sampling points by the same method as the above-mentioned bulk material, and then the probe is inserted from top to bottom at the sampling point. At the bottom, the sample enters the probe and the probe is pulled out to pour the sample. The shape of the probe tube is shown in Fig. 4. It is a truncated-conical iron pipe with a handle at the upper end, and its length should satisfy the depth of the entire pile.
4, the sampling of moving loose materials
(1) Key Law
This method is to take a certain amount of ore as a sample at regular intervals. After a certain period of time, the samples taken together are the samples in the time.
In the process of transporting block materials, one car can be selected at a certain number of cars, and some samples are taken according to the sampling method of the mine car. According to this method, the sample taken from the car left by each class is mixed and required to be taken out. The quantity is the sample of the class.
For example, the sampling of the shaft furnace roasting ore in a factory is to take two hoes from the two sides of the unloading machine every two hours, about one kilogram per ton. After mixing and preparing the samples, it is a sample of roasting ore.
(2) Intercept method
This method is a continuous or periodic (after a certain interval) interception of a part of the moving product as a sample, according to its interception method is divided into two types of downstream and interrupted, as shown in Figure 5.
The downstream interception method divides the flowing material into several tributaries along the mainstream, and finally one of the tributaries is used as a sample. This method is only suitable for very uniform materials, especially along the cross section.
In ore dressing production, the cut-off intercept method is used for sampling by equal sampling time, and equal materials are taken from the flow material in the cycle along the entire material flow width as samples. [next]
5, slurry sampling
The flow slurry in the beneficiation test and production process is generally taken by manual sampling tool according to the cut-off intercept method. Commonly used manual sampling tools include sampling boxes, sampling pots, and cylindrical sample spoons. The construction of the sampling box is shown in Figure 6.
When manufacturing the sampling box and sampling with the sampling box, the following matters should be noted:
1) The opening width of the sampling box should be 4~5 times larger than the large particles to be collected.
2) The inner wall of the sampling box is required to be smooth and easy to pour the material.
3) The volume of the sample box should not be less than the volume required to intercept the material at one time.
4) There should be a dedicated sampling box for each sampling point.
5) Sampling must be performed at equal intervals.
6) When sampling, the sample box should cross the material flow and pass the material flow at a constant speed.
7) Rinse the sample with water after pouring it out.
For the sampling of certain slurries, such as the slurry in the concentrator, a special sampler is used, and its structure is shown in Fig. 7.
The sampler consists of a container 2 with a lid 4, which is provided with a chain 3 on the lid, and a 3 to 5 mm rubber mat 5 is attached to the inner layer to seal the container. The rubber rod 6 is used as a container to be lifted into the slurry and the lid is automatically lifted. The container is fixed on a metal rod 1 of 3 to 4 meters in length, and a scale is drawn on the rod. When the sampler sinks to the required depth, the sample is taken by pulling the lid with a chain rope. [next]
6, mechanical sampling
In addition to manual sampling, sampling materials can be sampled by sampling machine. There are many types of sampling machines. According to the material size, shape and sample requirements, refer to relevant data for selection. Only two ferrous metal ore dressing plants are now manufactured by themselves. The sampling machines used for sampling in the production process are as follows:
(1) Scoop sampler
This kind of sampling machine used iron concentrate samples on the belt conveyor for many years in a certain plant's beneficiation workshop, and the effect is good. Its structure is shown in Figure 8.
The scoop sampler is sampled according to the principle of downstream interception. A vertical arm 2 is welded on the rotating shaft 1, and a sample spoon 3 is held at the top end of the arm. The sample spoon rotates in the opposite direction with the belt conveyor 4 as the shaft rotates. When the sample spoon is turned to the lower part to contact with the material, the sample is shoveled into the spoon. When it is turned to the upper part, the sample spoon is automatically tripped and the sample is discharged into the funnel 5, and is discharged from the funnel port, and the rotating shaft 1 is borrowed by the drum 6 After the frictional force formed by the movement of the load tape is rotated, it is rotated by the belt 8. Both the funnel 5 and the drive shaft are supported on the belt conveyor support 7.
The speed of the scoop sampler varies with the peripheral speed of the belt conveyor. The sampling amount can be changed according to the width of the scoop sampler and the number of scoops.
The machine is simple in construction, easy to manufacture and watch, suitable for wet material sampling.
(2) Reciprocating mechanical sampling machine
This mechanical sampler is generally used on a chute to take a slurry sample. The maximum allowable particle size in the slurry is 3 mm. The structure is shown in Fig. 9.
The machine is sampled according to the principle of current cut. The motor 1 directly drives a screw 2 to rotate, and pushes the slider 3 to reciprocate. The sampling tube 4 is connected under the slider for automatic sampling, and the steering and steering time of the motive is controlled by a double contact switch mounted on a mother machine. The sampling interval can be achieved by the time relay automatically turning on the power of the sampling machine to achieve one sampling.
In addition, when the sampler is working, there are bells and light signals to indicate whether the sampler is normal.
The technical conditions of the reciprocating sampler are:
Sampling tube opening width 5 mm
Number of samples 4, 8, 12, 16 times / hour
Sampling spoon interception speed 140, 280, 420, 560 mm / sec
The machine is simple in structure, easy to manufacture and reliable in operation.
Third, the sampling of auxiliary substances
In the firing test, the change of the gas composition in order to grasp the firing process, typically certain time to take the sample waste coal into the furnace and the gas discharge, is not the timing belt and take some reducing gas sample chamber of the combustion gas composition analysis done.
The inlet gas and the exhaust gas can be taken in the exhaust gas pipeline by connecting the bladder and the rubber ball together, and directly bonding the rubber pipe to the sample pipe of the gas pipe at the other end of the two balls Start sampling, before sampling, first remove the gas from the bladder and the two balls, then extract the gas, pump it again and then drain it again. The second pumping gas is used as a sample to fix the bladder and send the gas. analysis.
For the sampling of the reducing zone and the gas in the combustion chamber, a stainless steel pipe is connected to the other end of the two-ball, and the steel pipe is inserted into the furnace to take samples.
The bladder from which the sample is taken must be labeled before testing to avoid confusion during sampling and sample delivery. [next]
(2) Sampling of medicaments
In the flotation test, the reagents need to be sampled for component analysis, generally using batch sampling and batch inspection methods, so that the incoming chemicals can be stored in batches and used in batches. The method of taking various drugs depends on the state of the drug.
1. Sampling of loose medicaments
Such medicaments are generally packaged in bulk or in bags and drums. The sampling method for bulk medicaments is the same as for stationary powdered powder materials. For medicines used in containers and drums, 2 to 20% should be taken from the batch according to the quantity and type of the batch.
After using the bagged medicine, first pour out the medicine after the bag is taken out, mix it, take it out and put it into the bottle, and stuff it with wax to send it for chemical analysis.
2. Sampling of liquid medicament
Taking a liquid drug sample, attention should be paid to the stratification of the drug. It may be composed of liquids of different specific gravity and different compositions, and the sample must be representative of the properties of all liquid medicaments.
The liquid medicament is further divided into two types according to its flow state: fluid and viscous.
(1) Sampling of fluid medicaments
The method of adopting such a medicament mainly depends on the nature of the medicament and the storage container.
For the easy-mixing agent in the barrel, the barrel can be rolled and mixed before sampling. The chemicals that are difficult to mix in the tank and the car should be layered according to different heights, and then the corresponding weight ratio of each layer is obtained according to the sectional area of ​​each layer between different heights and the specific gravity of the liquid agent in the layer. The collected layers of the drug samples were then proportioned to represent samples of all liquid agents.
During the beneficiation test, the sampling of this kind of medicament is generally carried out with a 40~50 mm diameter glass tube with a scale. Before use, the finger is pressed at one end of the tube and the other end is inserted into the liquid medicine. After the depth, remove the finger, the liquid medicament is filled into the tube, and then the hand is held by the outer end of the tube, and the glass tube is lifted to pour out the liquid medicine as a sample. For the liquid medicine to be taken from a deep place in the container, it can be taken by a steel pipe sampling pipe, as shown in Fig. 10a, which is a steel pipe 1 having a diameter of about 20 mm and a length of several meters (depending on the sampling sinking degree). One end is welded by a thin plate into an enlarged tube 2, and the center of the tube is formed by a wire 4 with a plug 3.
When sampling, first plug the plug, insert the medicament to the required depth, push the plug with iron to 4, the medicament will enter the tube, then pull the iron ratio up to 4, so that the plug will close the nozzle, put the sampling tube, open the plug The sample can be poured out by the head.
The sampling of the aqueous solution sent to the sorting operation can be taken directly from the pipeline mouth, but the occluded pipeline should be opened before the mining, so that it can flow for a period of time before taking the sample.
(2) Sampling of viscous agents
Generally, it is packed in barrels and tank cars, and is divided into several layers. Therefore, samples should be taken in layers, and the same as the fluid sampled layered sampling calculation method, the pioneer is the corresponding weight ratio of each layer, and then proportionally represented. A sample of all liquid medicaments.
This agent can be taken in the same manner using the sampling tube shown in Figure 3-12a. However, for a drug having a relatively thick consistency close to a solid, it can be taken by a sampling tube as shown in Fig. 10b, which is composed of a steel pipe 1 which is sharpened at a tip end of about 20 mm in diameter, and an iron which has a sliding plug 2 at the end thereof.
When sampling, first insert the slider into the tip of the tube (slider can slide in the tube), then slowly insert the tube into the medicament, the medicament enters the tube, and pushes the slider up until it is inserted into the bottom of the medicament. The entire height of the medicament enters the tube, and a sampling tube is proposed. The wire is pushed down by hand, and the medicine in the tube is layered by a sliding plug to obtain a sample of each layer of the medicament.
(3) Sampling of water
In the flotation test, in order to grasp the influence of water on flotation, it is necessary to collect samples of water for analysis and testing.
Water samples are generally taken from water sources and water supply lines. When taking a water sample from a water pipe, the pipe head is opened to allow the stagnant water to flow for a period of time before taking the sample.
Before sampling the water sample, the sampling bottle is cleaned. After the water sample is taken, the sampling time and sampling location are indicated on the water sample bottle.
For the beneficiation test with mixed water, if the water in a flotation plant of a factory is mixed with blast furnace circulating water, rolling steel circulating water and washing water, in addition to the mixed water sampling, a single water sample should be taken for analysis. The impact of each individual water on the flotation process.
Drone Accessory,Flight Controller,Universal Drone Controller,Agriculture Drone Sprayer Parts
Dongying Tianqi Technology Co., Ltd. , https://www.uav5.com