CN102826695B - Scheelite beneficiation wastewater treatment process - Google Patents

Abstract

The invention relates to a process for treating scheelite beneficiation wastewater. The scheelite beneficiation wastewater treatment process provided by the present invention uses electrolysis to remove most of the water glass and most of the organic chemicals, then adds a coagulant to further settle to remove the water glass and organic chemicals, and finally adds an oxidant to remove the remaining organic chemicals in the wastewater . The process provided by the present invention has a removal rate of water glass of over 94.5%, a removal rate of organic agents for mineral processing of over 98%, and a stable effluent quality, which exceeds the first-level discharge standard requirements of GB8978-1996 "Comprehensive Wastewater Discharge Standard", and the treated water can be recycled. Used in beneficiation process. The method of the invention has stable treatment effect, high efficiency, and simple operation; the process flow is short, the occupied area is small; the cost is low, and energy saving and environmental protection are achieved.

Description

Scheelite beneficiation wastewater treatment process

technical field

The invention relates to a process for treating scheelite beneficiation wastewater.

Background technique

Water glass is an inorganic colloid, which is the most commonly used inhibitor and dispersant in flotation operations. The existence of water glass makes it difficult to clarify the tailings water, and some refractory organic chemicals contained in the tailings water make it difficult to reuse the tailings water in the scheelite beneficiation industry. The beneficiation water consumption per ton of ore is about 4 tons. The concentration of water glass in the tailings wastewater of the scheelite beneficiation industry is above 2000mg/L, and the COD _cr concentration caused by other organic chemicals is generally above 200mg/L. The steps of the commonly used scheelite beneficiation wastewater treatment process are as follows: (1) Add lime milk to the tailings water, adjust the pH value to above 11.0, and then transport the tailings water to the tailings pond, where the slag water is separated and precipitated, The tailings wastewater is discharged into the regulating pool of the wastewater treatment station. (2) The tailings wastewater entering the adjustment tank of the wastewater treatment station is lifted to the reaction tank through the pump, and flocculants (such as PAC, PAM) are added, and the dosage is greater than 80mg/L. After sufficient flocculation, the tailings wastewater flows into Inclined plate sedimentation tank. (3) Adjust the pH value of the tailings wastewater entering the inclined plate sedimentation tank to 6.0-9.0, and then discharge it after filtering. The above-mentioned conventional treatment method can make the discharge of tailings water basically comply with the discharge standard, but there are the following disadvantages: 1. It is difficult to reuse the treated effluent. Due to the incomplete removal of water glass and organic chemicals in the tailings wastewater, the beneficiation index is affected, and the treated water is difficult to reuse. 2. Unable to meet emission standards stably. As the atmospheric precipitation directly enters the tailings pond, the water quality index of the tailings pond drainage changes greatly, resulting in unstable discharge water indicators of the treatment station, and it is difficult to discharge in a stable manner. 3. High operating costs. The dispersing effect of water glass makes the flocculation and sedimentation of tailings wastewater difficult. It is necessary to add lime milk to adjust the pH value above 11 and add a large amount of flocculant (>80mg/L), and the pH value of the effluent needs to be adjusted, resulting in high operating costs for wastewater treatment. In water-deficient areas, tailings water is reused for mineral processing, which makes the mineral processing enterprises pay the price of reducing the metal recovery rate, resulting in waste of resources, which is not conducive to energy conservation and environmental protection; in addition, the dispersion of water glass makes it difficult to flocculate and settle tailings wastewater. Dosing a large amount of flocculant leads to high cost of wastewater treatment.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a scheelite mineral processing wastewater treatment process. The water quality of the scheelite mineral processing wastewater treated by the process of the present invention meets the first-level discharge standard of GB8978-1996 "Comprehensive Wastewater Discharge Standard", and can Reuse in beneficiation.

The scheelite beneficiation wastewater treatment process of the present invention has the following steps:

a. Add a coagulant to the waste water, then electrolyze, and settle to remove most of the water glass and most of the organic agents. The amount of the coagulant is 0.01 to 0.02 times the quality of the water glass in the waste water, and the once-treated water glass is obtained. waste water;

B, add coagulant aid in the once-treated waste water of step a, further sedimentation removes water glass and organic agent, wherein the consumption of coagulant aid is 15～20mg/l, obtains the waste water through secondary treatment;

c. Add an oxidizing agent to the secondary treated wastewater in step b to remove the remaining organic chemicals in the water, wherein the amount of the oxidizing agent is 3 to 4 times the quality of the organic chemicals in the secondary treated wastewater, and filter to obtain recycled water.

As a further improvement of the present invention, in step a, a coagulant is firstly added to the waste water, followed by electrolysis.

As a further improvement of the present invention, the amount of the coagulant used is 0.01-0.02 times the mass of water glass in the waste water.

Electrolysis The scheelite beneficiation wastewater treatment process of the present invention uses an electrolytic method to treat scheelite beneficiation wastewater, and the reaction equation is as follows:

Electrolysis can break the molecular chain of organic macromolecule agent, provide sufficient carbon source for the decomposition of water glass, thereby greatly accelerated the decomposition and sedimentation speed of water glass, and the whole reaction process is completely completed within 3 to 5 minutes; therefore, the white water of the present invention The tungsten beneficiation wastewater treatment process does not require destabilization treatment of water glass, and the treatment effect is not affected by the concentration of water glass in the wastewater. The removal rate of water glass is above 94.5%, and the removal rate of organic chemicals in mineral processing is above 98%. Stable, exceeding the requirements of the first-level discharge standard of GB8978-1996 "Sewage Comprehensive Discharge Standard", and the treated water can be reused for the mineral processing process. The method of the invention has stable treatment effect, high efficiency, and simple operation; the process flow is short, the occupied area is small; the cost is low, and energy saving and environmental protection are achieved.

Description of drawings

Fig. 1 is the process flow diagram of embodiment 2.

Detailed ways

In order to facilitate understanding of the present invention, the following examples are described. It should be noted that the following examples are merely examples and should not be considered as limiting the scope of the present invention.

Example 1 10,000 liters of scheelite beneficiation wastewater, the test data are shown in Table 1, the wastewater is directly electrolyzed to decompose water glass and organic chemicals, and the wastewater after primary treatment is obtained; coagulant aid (PAM) is added to the wastewater after primary treatment 150g, settling to remove water glass, and obtain waste water through secondary treatment; See Table 1 for the detection data of waste water through secondary treatment; Add oxidant (H ₂ O ₂ ) 2.1kg in waste water through secondary treatment again, make The remaining organic matter in the water is fully oxidized and filtered to return water. The measured data of reused water is shown in Table 1, which exceeds the requirements of the first-level discharge standard of GB 8978-1996 "Integrated Wastewater Discharge Standard". The reclaimed water is used in the beneficiation process, which has the same effect as the use of fresh water for beneficiation, and does not affect the beneficiation index.

Table 1 The detection data of the scheelite beneficiation wastewater, secondary treated water and reused water in Example 1

Example 2 With the scheelite mineral processing wastewater in Example 1, add 26 kg of coagulant (PAC) to the wastewater, then perform electrolysis to decompose water glass and organic agents, and obtain once-treated wastewater; in the once-treated wastewater Add 200g of coagulation aid (PAM), settle to remove water glass, and obtain secondary treated wastewater; the test data of the secondary treated wastewater is shown in Table 2; then add oxidant (H ₂ O ₂ ) 2.2kg, to fully oxidize the remaining organic matter in the water, and filter to obtain recycled water (see Figure 1 for the process flow chart). The measured data of reused water is shown in Table 2, which exceeds the requirements of the first-level discharge standard of GB 8978-1996 "Integrated Wastewater Discharge Standard". The reclaimed water is used in the beneficiation process, which has the same effect as the use of fresh water for beneficiation, and does not affect the beneficiation index.

Table 2 The detection data of the scheelite beneficiation wastewater, secondary treated water and reused water in Example 2

Example 3 10,000 liters of scheelite beneficiation wastewater, 16.5kg of coagulant (PAC) was added to the wastewater, and electrolysis was carried out to decompose water glass and organic agents to obtain once-treated wastewater; Add 180g of coagulant aid (PAM), settle to remove water glass, and obtain secondary treated wastewater; the test data of the secondary treated wastewater is shown in Table 2; then add oxidant (H ₂ O ₂ ) 2.3kg, to fully oxidize the remaining organic matter in the water, and filter to obtain recycled water. The measured data of recycled water is shown in Table 3, exceeding the requirements of the first-level discharge standard of GB 8978-1996 "Integrated Wastewater Discharge Standard". The reclaimed water is used in the beneficiation process, which has the same effect as the use of fresh water for beneficiation, and does not affect the beneficiation index.

Table 3 The detection data of scheelite beneficiation wastewater, secondary treated water and reused water in Example 3.

Claims (3)

1. A process for the treatment of scheelite mineral processing wastewater, the steps are as follows: a. Electrolyze the waste water, remove most of the water glass and most of the organic agents by sedimentation, and obtain the once-treated waste water; B, add coagulant aid in the once-treated waste water of step a, further sedimentation removes water glass and organic agent, wherein the consumption of coagulant aid is 15～20mg/l, obtains the waste water through secondary treatment; c. Add an oxidizing agent to the secondary treated wastewater in step b to remove the remaining organic chemicals in the water, wherein the amount of the oxidizing agent is 3 to 4 times the quality of the organic chemicals in the secondary treated wastewater, and filter to obtain recycled water. 2. The process for treating scheelite beneficiation wastewater according to claim 1, characterized in that: in step a, a coagulant is first added to the wastewater, and then electrolyzed. 3. The process for treating scheelite beneficiation wastewater according to claim 2, characterized in that: the amount of coagulant is 0.01-0.02 times the mass of water glass in the wastewater.

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