Flotation dosing control

The amount of dosing in the flotation process directly affects the flotation index. It is still the main control most amount of non-ferrous metal flotation plant to control the flotation process. Regulating the dosing volume of flotation operations can capture more useful metals and inhibit unwanted minerals, which is an important way to ensure flotation indicators. On the other hand, the amount of the drug is easily controlled, and the method is simple, and thus the drug adjustment is used as the main control means. Here are two ways to control the amount of flotation. One is to use a microcomputer-based dosing machine to achieve regular dosing. One is to use the current-carrying analyzer (or semi-online analyzer) to calculate the corresponding dosing amount by measuring the metal grade, and to control it. At the same time, it can control the dose of 5 ~ 48 points, the effect is remarkable, and the metal recovery can be improved. Rate and save a lot of potions.

First, the microcomputer feeding machine

The microcomputer dosing machine controls the on-off time of the solenoid valve to achieve timing and quantitative dosing for a plurality of dosing points, such as 48 points, and displays relevant parameters of each dosing point on the CRT screen. This improves the dosing control, and the set values ​​can be modified in time according to the changes in the process parameters during the dosing process. Domestic WG-10, BBH-1, DGY, WGY-1, WGY-2 and other types of dosing machines.

For example, the BBH-1 type dosing machine is composed of a quantitative bottle device controlled by a solenoid valve, a TP-801B single board machine, a CRT' display and a printer.

The solenoid valve and the dosing bottle device are shown in Figure 5-4-4, which is the actuator of the dosing machine. The flotation reagent solution is stored in the drug storage tank at a certain height. The siphon connects the reservoir to the dosing bottle via a solenoid valve. When the solenoid de-energized, the discharge solenoid drop tube blockage drug, drug kits rely on fixed pressure reservoir liquid level, the agent through the siphon, the electromagnetic valve flows quantitative bottles until full. The volume of the vial of the vial is determined based on the amount of the medicament and the level of the medicament in the reservoir. When the solenoid valve is energized, the electromagnet is lifted, and the siphon tube at the upper end of the solenoid valve is blocked, and the medicament in the medicine storage tank cannot flow out. The outlet of the lower end of the solenoid valve is opened, and the medicament in the metering bottle flows into the discharge tube through the solenoid valve and enters the flotation tank.

Three outputs of PS0, PS 5, and PS6 of the TP-801 single board machine 1/0 decoder are connected, and three PIO chips are connected. When the PIO is output as mode 0, the three PIOs have a total of 48 outputs and are connected to 48 solenoid valve drive circuits. When an output of the PIO is set to "1", the output is high (10 volts volts), the solenoid of the solenoid valve is energized by the driver, and the electromagnet is lifted. When the output of a certain point of PIO is “0”, the output is low level [0 volt], the solenoid valve coil is de-energized, the electromagnet falls to block the discharge tube, and the quantitative bottle starts to charge again. The block diagram is shown in Figure 5-4-5.

The single board machine displays the relevant data of the dosing on the CRT screen. The dosing amount per minute per minute and the cumulative dosing amount in 8 hours are printed every 8 hours. The dosing time of this method can reach 0.1 second, and the dosing precision can reach 0.1 ml.

Second, according to the proportion of ore to the ore to control the amount of dosing

This is the simplest way to control, as shown in Figure 5-4-6. The computer converts the flow rate and concentration signal of the ore slurry into the dry ore volume of the ore, and calculates the required amount of the medicament according to the dry ratio and the predetermined ratio (dosage per ton of ore) as a given value of the flow regulator. The medicament is adjusted by the regulator, and the medicament is dispensed through the dispenser to the dosing point of each flotation cell group. With this control method, the concentration of the drug should be kept constant, otherwise the concentration compensation should be performed. The liquid level of the reservoir and the pressure of the reagent circulation circuit need to be kept constant.

The signal for the ore amount can also be directly taken from the output of the ore belt scale. As shown in Figure 5-4-7. In the absence of a computer, a conventional meter can be used instead of a computer.

Third, according to the proportion of metal in the ore mine to control the amount of dosing

For a drug such as a collector , the added amount is not only related to the amount of ore, but also related to the metal grade required in the ore. Therefore, it is generally used to control the dosing amount according to the proportion of the metal amount of the ore. As shown in Figure 5-4-8. The dosing ratio (dosing amount per ton of metal) can be given manually or according to a certain relationship according to the original ore grade.

4. Control the dosage according to the amount of metal in the ore and the grade of tailings.

The flotation process is more complicated. The two simple feedforward controls mentioned above cannot overcome the influence of other disturbances, and only the medicament can be roughly controlled. Therefore, it must be corrected by other parameters that reflect the effect of flotation. Among these parameters, the most commonly used is the tailings grade. 5-4-9 is a control block diagram of FIG agents lead zinc flotation employed. It controls the various dosages according to the amount of metal in the ore and the grade of the tailings before feeding. The control formula is:

Trend, its value is 1,0,-1.

5. Control the dosage according to the recovery rate and concentrate grade

The useful mineral content in tailings can reflect the effect of flotation operation to a certain extent, but when the mineral properties change, it does not guarantee that the flotation process reaches a predetermined index. Therefore, it is necessary to further control the amount of the drug directly according to the recovery rate and the concentrate grade.

Figure 5-4-10 shows a control block diagram of the lead-zinc flotation circuit collector. It is based on the previous bond-backward control approach.

Adjustment limits are provided throughout the system. When the calculated added amount exceeds the limit value, the computer notifies the operator. In addition, a certain dead zone is usually specified near a given value to avoid oscillation of the regulation loop due to some ambiguous error.