阅读说明：本技术 一种中性地浸采铀浸出液除铁方法 (Iron removal method for neutral in-situ leaching uranium extraction leachate ) 是由 陈乡 廖文胜 王立民 李坡 王振 于 2020-12-23 设计创作，主要内容包括：本发明属于铀矿采冶技术领域,具体涉及一种中性地浸采铀浸出液除铁方法,包括以下步骤：步骤1：配置氧化剂,氧化剂采用二氯异氰尿酸钠,将其溶解成水溶液；步骤2：配置絮凝剂,絮凝剂采用聚合氯化铝,将其溶解成水溶液；步骤3：将氧化剂注入浸出液管道；步骤4：将絮凝剂注入浸出液管道；步骤5：将被氧化絮凝的浸出液注入二级精密过滤器；步骤6：过滤回注,过滤后浸出液不经静置,经过铀提取工艺后直接回注至地下。本发明方法可以将中性浸出液中的铁由5～20mg/L降低到0.5mg/L以下。(The invention belongs to the technical field of uranium mining and metallurgy, and particularly relates to a method for removing iron from neutral in-situ leaching uranium leaching liquid, which comprises the following steps: step 1: preparing an oxidant, wherein the oxidant is sodium dichloroisocyanurate, and the sodium dichloroisocyanurate is dissolved into an aqueous solution; step 2: preparing a flocculating agent, wherein the flocculating agent is polyaluminium chloride and is dissolved into an aqueous solution; and step 3: injecting an oxidant into the leachate conduit; and 4, step 4: injecting a flocculating agent into a leaching solution pipeline; and 5: injecting the oxidized and flocculated leachate into a secondary precision filter; step 6: and (4) filtering and reinjecting, wherein the leachate is not kept stand after being filtered, and is directly reinjected to the underground after being subjected to a uranium extraction process. The method can reduce the iron content in the neutral leaching solution from 5-20 mg/L to below 0.5 mg/L.)

1. A method for removing iron from neutral in-situ leaching uranium extraction leachate is characterized by comprising the following steps: the method comprises the following steps:

step 1: preparing an oxidant, wherein the oxidant is sodium dichloroisocyanurate, and the sodium dichloroisocyanurate is dissolved into an aqueous solution;

step 2: preparing a flocculating agent, wherein the flocculating agent is polyaluminium chloride and is dissolved into an aqueous solution;

and step 3: injecting an oxidant into the leachate conduit;

and 4, step 4: injecting a flocculating agent into a leaching solution pipeline;

and 5: injecting the oxidized and flocculated leachate into a secondary precision filter;

step 6: and (4) filtering and reinjecting, wherein the leachate is not kept stand after being filtered, and is directly reinjected to the underground after being subjected to a uranium extraction process.

2. The method for removing iron from neutral in-situ leaching uranium extraction leachate according to claim 1, wherein: in the step 1, an oxidant is dissolved into a 1-20% solution.

3. The method for removing iron from neutral in-situ leaching uranium extraction leachate according to claim 1, wherein: in the step 2, the flocculating agent is dissolved into 1-30% solution.

4. The method for removing iron from neutral in-situ leaching uranium extraction leachate according to claim 1, wherein: in the step 3, the injection amount of the effective oxidant is 50-200 mg/L.

5. The method for removing iron from neutral in-situ leaching uranium extraction leachate according to claim 4, wherein: in the step 3, the oxidation time is controlled to be 10-20 s.

6. The method for removing iron from neutral in-situ leaching uranium extraction leachate according to claim 1, wherein: in the step 4, the injection amount of the effective flocculating agent is 20-120 mg/L.

7. The method for removing iron from neutral in-situ leaching uranium mining leachate according to claim 6, wherein: in the step 4, the flocculation time is controlled to be 1-30 min.

8. The method for removing iron from neutral in-situ leaching uranium extraction leachate according to claim 1, wherein: in the step 5, the primary filtering precision is 20-50 μm, and the secondary filtering precision is 5-15 μm.

Technical Field

The invention belongs to the technical field of uranium mining and metallurgy, and particularly relates to a method for removing iron from a neutral in-situ leaching uranium leaching solution.

Background

The neutral in-situ leaching uranium mining process is suitable for northern sandstone uranium ores, and the ore forming mechanism of the sandstone uranium ores is closely related to iron. Along with the injection of leaching agents such as oxygen, carbon dioxide and the like, the iron element is precipitated while the underground uranium-bearing ore layer is leached. The iron element is changed from solid state to liquid state, and is continuously oxidized from divalent state to trivalent state, so that various unfavorable phenomena such as pumping well blockage, resin hardening and the like are caused.

The conventional iron removal process comprises a manganese sand filtration method, an oxidation precipitation method and the like. However, the leaching industry needs to retain uranium while removing iron, and the two methods can cause loss of uranium while removing iron.

Therefore, it is necessary to develop a suitable method for reducing the iron concentration in the leachate at the surface, preventing the blockage of the pores caused by the reinjection process, and at the same time, maximally retaining the effective element uranium.

Disclosure of Invention

The invention aims to provide a method for removing iron from neutral in-situ leaching uranium extraction leachate, which can remove iron from in-situ leaching mine leachate and protect effective element uranium.

The technical scheme of the invention is as follows:

a method for removing iron from neutral in-situ leaching uranium extraction leachate comprises the following steps:

step 1: preparing an oxidant, wherein the oxidant is sodium dichloroisocyanurate, and the sodium dichloroisocyanurate is dissolved into an aqueous solution;

step 2: preparing a flocculating agent, wherein the flocculating agent is polyaluminium chloride and is dissolved into an aqueous solution;

and step 3: injecting an oxidant into the leachate conduit;

and 4, step 4: injecting a flocculating agent into a leaching solution pipeline;

and 5: injecting the oxidized and flocculated leachate into a secondary precision filter;

step 6: and (4) filtering and reinjecting, wherein the leachate is not kept stand after being filtered, and is directly reinjected to the underground after being subjected to a uranium extraction process.

Preferably, in the step 1, the oxidant is dissolved into a 1-20% solution.

Preferably, in the step 2, the flocculating agent is dissolved into a 1-30% solution.

Preferably, in the step 3, the injection amount of the effective oxidant is 50-200 mg/L.

Preferably, in the step 3, the oxidation time is controlled to be 10-20 s.

Preferably, in the step 4, the injection amount of the effective flocculating agent is 20-120 mg/L.

Preferably, in the step 4, the flocculation time is controlled to be 1-30 min.

Preferably, in the step 5, the primary filtering precision is 20-50 μm, and the secondary filtering precision is 5-15 μm.

The invention has the following remarkable effects:

(1) the method can reduce the iron content in the neutral leaching solution from 5-20 mg/L to below 0.5 mg/L.

(2) The method can reduce the loss rate of neutral leaching solution uranium with uranium concentration of 10-50 mg/L to 10-30% while removing iron.

(3) The invention provides a feasible method for protecting the uranium concentration while removing iron for the first time.

Detailed Description

The present invention will be described in further detail with reference to specific examples.

A method for removing iron from neutral in-situ leaching uranium extraction leachate comprises the following steps:

step 1: configuring an oxidizing agent

The oxidant is sodium dichloroisocyanurate, and the sodium dichloroisocyanurate is dissolved into 1-20% solution.

Step 2: preparation of flocculant

The flocculating agent is polyaluminium chloride which is dissolved into 1-30% solution.

And step 3: oxidant is injected into the leaching solution pipeline by adopting a metering pump

The injection amount of the effective medicament is 50-200 mg/L, and the oxidation time is controlled to be 10-20 s.

And 4, step 4: the flocculating agent is injected into the leaching liquid pipeline by adopting a metering pump

The injection amount of the effective medicament is 20-120 mg/L, and the flocculation time is controlled within 1-30 min.

And 5: injecting the oxidized and flocculated leachate into a secondary precision filter

The primary filtration precision is 20-50 μm, and the secondary filtration precision is 5-15 μm.

Step 6: filtration reinjection

And directly reinjecting the filtered leachate to the underground after a uranium extraction process without standing.

Example 1

Neutral leaching uranium ore in Xinjiang by using CO₂+O₂And (4) process mining. The flow of the leaching solution is 5m³And h, the iron content in the leachate is 8-10 mg/L, and the uranium concentration is 8-12 mg/L.

More than 90% of the iron is injected back into the ground using conventional processes.

By applying the method, the total iron content in the treated leachate is reduced to 0.35mg/L, and the uranium concentration is kept at 9 mg/L.

The method comprises the following steps:

step 1: and (4) preparing an oxidizing agent. The oxidant is sodium dichloroisocyanurate, and the sodium dichloroisocyanurate is dissolved into 10 percent solution.

Step 2: and (5) preparing a flocculating agent. The flocculant is polyaluminium chloride, and is dissolved into 10% solution.

And step 3: and (3) injecting an oxidant into the leachate pipeline by adopting a metering pump, wherein the injection amount of the effective medicament is 150 mg/L. The oxidation time was controlled at 10 s.

And 4, step 4: and (3) injecting the flocculating agent into a leachate pipeline by adopting a metering pump, wherein the injection amount of the effective medicament is 70 mg/L. Flocculation time is controlled at 1 min.

And 5: and injecting the oxidized and flocculated leachate into a secondary precision filter. The primary filtration precision is 20 μm, and the secondary filtration precision is 5 μm.

Step 6: and directly reinjecting the filtered leachate to the underground after a uranium extraction process without standing.

The total iron content of the leachate is reduced to 0.35mg/L by the process, the uranium concentration is kept at 9mg/L, and the leachate is reinjected to the ground after being filtered through a uranium extraction process.

Example 2

Leaching uranium ore in certain neutral place of internal Mongolia by using CO₂+O₂And (4) process mining. The flow of the leaching solution is 6.4m³And h, the iron content in the leachate is 10-15 mg/L, and the uranium concentration is 25-35 mg/L.

More than 90% of the iron is injected back into the ground using conventional processes.

By applying the method, the total iron content in the treated leachate is reduced to 0.46mg/L, and the uranium concentration is averagely kept at 26 mg/L.

The method comprises the following steps:

step 1: and (4) preparing an oxidizing agent. The oxidant is sodium dichloroisocyanurate, and the sodium dichloroisocyanurate is dissolved into 10 percent solution.

Step 2: and (5) preparing a flocculating agent. The flocculant is polyaluminium chloride, and is dissolved into 10% solution.

And step 3: and injecting an oxidant into the leachate pipeline by adopting a metering pump, wherein the injection amount of the effective medicament is 180 mg/L. The oxidation time was controlled at 15 s.

And 4, step 4: and (3) injecting a flocculating agent into a leachate pipeline by adopting a metering pump, wherein the injection amount of an effective medicament is 120 mg/L. Flocculation time is controlled at 4 min.

And 5: and injecting the oxidized and flocculated leachate into a secondary precision filter. The primary filtration precision is 20 μm, and the secondary filtration precision is 10 μm.

Step 6: and directly reinjecting the filtered leachate to the underground after a uranium extraction process without standing.

The total iron content of the leachate is reduced to 0.46mg/L through the process, the uranium concentration is kept at 26mg/L, and the leachate is reinjected to the ground after being filtered through a uranium extraction process.