CN103550903A - Harmless treatment method for multi-metal coexisting chromium-containing waste - Google Patents

Abstract

The invention discloses a harmless treatment method for multi-metal coexisting chromium-containing waste. The harmless treatment method comprises the following steps: (1) preparing the multi-metal coexisting chromium-containing waste raw material; (2) pulping the prepared material to prepare mixed pulp, and then adding concentrated sulfuric acid into the mixed pulp; (3) adjusting the pH (potential of Hydrogen) to be 3.5-3.8 by using calcium carbonate to produce iron-chromium-alum precipitate, filtering, wherein the content of Fe in the filtrate is 0.05-0.1 g/L, and the content of the Cr in the filtrate is 0.1-0.5 g/L, and finally recovering other metals by using a conventional means; (4) washing the iron-chromium-alum precipitate under the condition of pH of 6-9 to obtain stable iron, chromium and alum, and detecting leaching toxicity to make sure that the leaching toxicity of total chromium is less than 5 mg/L, the leaching toxicity of Cu is less than 10 mg/L, the leaching toxicity of Zn is less than 10 mg/L, and the leaching toxicity of Ni is less than 5mg/L so as to reach the national harmless standard.

Description

The method for innocent treatment containing chromium refuse that a kind of many metals coexist

Technical field

The harmless resource utilization that the present invention relates to a kind of multiple metal discarded object is processed recovery method, relates in particular to the method for innocent treatment containing chromium refuse that a kind of many metals coexist.

Background technology

Existing non-ferrous metal hazardous waste disposal technology, has solidify & bury, throws sea, the technology such as burning, this class technology existence occupy cultivated land, waste resource, cost high, have shortcomings such as secondary environmental pollution hidden danger at a specified future date.The harmless recycling technology of non-ferrous metal danger wastes is the emphasis of studying both at home and abroad always.Prior art has pyrogenic process technology and Wet technique two classes.The former cost is higher, and existing Wet technique main technological steps comprises: leaching-Separation of Solid and Liquid-purification enrichment-extraction metal or compound.Leaching is that non-ferrous metal waste material is selectively leached, and makes heavy metal composition stripping wherein.Leaching dissolving mainly contains acidleach and ammonia soaks two kinds of techniques.The acid-hatching of young eggs is one of leaching method conventional in hydrometallurgy, and its reaction time is short, and leaching efficiency is high, by the most of metal object mass-energy of acidleach with ionic state or the stripping of complex ion state.It is to add by salt and make leaching agent with ammonia or ammonia that ammonia soaks, and higher to the sealing requirements of device, its superiority is the metals such as alternative dissolved copper, zinc, brill, silver, nickel, and iron, chromium, calcium, aluminium etc. are mostly suppressed in and leach in recrement.Metal target enters after liquid phase, utilizes the modes such as directly filtration or pressurization suction filtration to make leachate and residue Separation of Solid and Liquid, then separation and Extraction after the copper in leachate, nickel purification enrichment out.The purification enrichment technology of comparative maturity comprises: the methods such as chemical precipitation, solvent extraction, ion-exchange, after purification enrichment step completes, just can carry out in separated recovery non-ferrous metal waste material with crystallisation the metals resources such as copper, nickel, but products therefrom is mainly the hydroxide of metal or the salt of metal, if product purity is had to requirements at the higher level, can adopt hydrazine reduced separation method, hydrogen reduction partition method, electrolysis or crystallisation, finally the form with metal or slaine reclaims, but production cost is increased.Containing chromium treatment of wastes produced method, have at present: wet reducing, fire reduction, solidify & bury etc., but be all mainly for chromium, will cause waste resource and increase environmental pressure when having various metals to coexist.

Summary of the invention

In view of above-mentioned weak point, the object of the present invention is to provide a kind of method of resource of not only having realized the innoxious while of chromium but also realized other metal when many metals such as Fe, Cu, Cr, Ni, Zn, Go coexisting.

In order to achieve the above object, the present invention has adopted following technical scheme: the method for innocent treatment containing chromium refuse that a kind of many metals coexist comprises the following steps:

(1) what many metals are coexisted prepares burden containing chromium waste material, makes Cr VI: Zero-valent Iron=1:1.5, the ratio of the total iron of Fe:Cr=2.5-3.5:1(and total chromium, comprises Cr VI and Zero-valent Iron);

(2) what the many metals after batching are coexisted mixes and makes mixed serum by the weight portion proportioning of 1:3-5 with water containing chromium waste material, then in mixed serum, adds 98% concentrated sulfuric acid, and 60 ℃ of temperature control <, to mixed serum pH1.0-1.5; Adjust Fe+Cr < 10g/L in mixed serum; Concrete method of adjustment is: if in mixed serum during Fe+Cr >=10g/L, be just diluted with water.The chemical reaction occurring in this step is:

XOH+H ₂SO ₄

XSO ₄+H ₂O

H ₂SO ₄+Fe H ₂+FeSO ₄

Cr ⁶⁺+Fe ²⁺

Cr ³⁺+Fe ³⁺

Wherein X is metallic element (Cu, Zn, Co, Ni, Fe etc.).

(3) with calcium carbonate, adjust mixed serum pH3.5-3.8, generate redingtonite precipitation, filter Fe:0.05-0.1g/L in filtrate; Cr:0.1-0.5g/L, finally adopts conventional means to reclaim other metals again; The chemical reaction occurring in this step is:

Fe ³⁺+Cr ³⁺+OH ^-+H ₂O ?(Fe ₂O ₃) _xCr ₂O ₃·H ₂O

(4) redingtonite is deposited under pH6-9 condition and is washed, obtain stable redingtonite, check Leaching: total chromium < 5mg/L; Cu < 10mg/L; Zn < 10mg/L; Ni < 5mg/L reaches national innoxious standard.

Beneficial effect of the present invention is:

(1) whole flow process does not heat, and redingtonite strainability is good, is easy to washing, and other metal toxicity is very easily up to standard.

(2) be easy to procedure, chromium is stablized the innoxious standard that reaches.

(3) self-produced excessive FeSO in flow process ₄guaranteed Cr ^{+ 6}removing toxic substances 100%, reduced production cost.

Accompanying drawing explanation

Fig. 1 is the method for innocent treatment flow chart containing chromium refuse that many metals coexist.

The specific embodiment

Embodiment:

The method for innocent treatment flow chart containing chromium refuse that many metals coexist as shown in Figure 1, is specially:

Many metals are coexisted containing chromium waste material HW17, HW21, HW22 prepare burden, and (meaning of batching is exactly that raw material is before mixing with water, in raw material, add the batchings such as Zero-valent Iron, make it meet Cr VI and Zero-valent Iron reaches certain proportion, be convenient to subsequent technique flow process), make Cr VI: Zero-valent Iron=1:1.5, the ratio of the total iron of Fe:Cr=2.5-3.5:1(and total chromium, comprises Cr VI and Zero-valent Iron); What the many metals after batching were coexisted mixes and makes mixed serum by the weight portion proportioning of 1:3-5 with water containing chromium waste material HW17, HW21, HW22, then in mixed serum, add 98% concentrated sulfuric acid, 60 ℃ of temperature control <, to mixed serum pH1.0-1.5; Adjust Fe+Cr < 10g/L in mixed serum; Concrete method of adjustment is: if in mixed serum during Fe+Cr >=10g/L, be just diluted with water.With calcium carbonate, adjust mixed serum pH3.5-3.8, generate redingtonite precipitation, filter Fe:0.05-0.1g/L in filtrate; Cr:0.1-0.5g/L, finally adopts conventional means to reclaim other metals again; Redingtonite is deposited under pH6-9 condition and is washed, obtain stable redingtonite, check Leaching: total chromium < 5mg/L; Cu < 10mg/L; Zn < 10mg/L; Ni < 5mg/L reaches national innoxious standard.

The concrete supplies consumption of test example 1 is to expect 1 ton:

Table 1 material major metal component list

Consume: H ₂sO ₄: 320Kg CaCO ₃: 0.2t H ₂o ₂: 30Kg Fe:12Kg

This section obtains Cu powder 9.8Kg, direct yield 98%, redingtonite 161Kg, direct yield 98.3%.

Table 2 redingtonite [(Fe ₂o ₃) _xcr ₂o ₃h ₂o] main component table

Each valuable metal is less than 0.1% this section of operation loss, meets the domestically leading level of metallurgical technology completely.

Table 3 is disposed front and back Leaching contrast table

The concrete supplies consumption of test example 2 (in 1 ton of the material for preparing)

Table 4 material major metal component list

Consume: H ₂sO ₄: 332Kg CaCO ₃: 0.27t H ₂o ₂: 32Kg Fe:17Kg

This section obtains Cu powder 14.7Kg, direct yield 98%, redingtonite 173.3Kg, direct yield 98.4%.

Table 5 redingtonite [(Fe ₂o ₃) _xcr ₂o ₃h ₂o] main component table

Each valuable metal is less than 0.1% this section of operation loss, meets the domestically leading level of metallurgical technology completely.

Table 6 is disposed front and back Leaching contrast table

Claims (1)

1. the method for innocent treatment containing chromium refuse that more than, metal coexists, is characterized in that: the method comprises the following steps:

(1) what many metals are coexisted prepares burden containing chromium waste material, makes Cr VI: Zero-valent Iron=1:1.5, Fe:Cr=2.5-3.5:1;

(2) what the many metals after batching are coexisted mixes and makes mixed serum by the weight portion proportioning of 1:3-5 with water containing chromium waste material, then in mixed serum, adds the concentrated sulfuric acid, and 60 ℃ of temperature control <, to mixed serum pH1.0-1.5; Adjust Fe+Cr < 10g/L in mixed serum;

(3) with calcium carbonate, adjust mixed serum pH3.5-3.8, generate redingtonite precipitation, filter Fe:0.05-0.1g/L in filtrate; Cr:0.1-0.5g/L, finally adopts conventional means to reclaim other metals again;

(4) redingtonite is deposited under pH6-9 condition and is washed, obtain stable redingtonite, check Leaching: total chromium < 5mg/L; Cu < 10mg/L; Zn < 10mg/L; Ni < 5mg/L reaches national innoxious standard.

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