CN1138704C

CN1138704C - Method for treatment of waste lye

Info

Publication number: CN1138704C
Application number: CNB001084836A
Authority: CN
Inventors: 刘光利; 丁雪红; 牛进龙; 孙元俊; 刘发强; 胡秀燕
Original assignee: Lanzhou Petrochemical Institute Of China Petrochemical Corp; Petrochina Lanzhou Petrochemical Co
Current assignee: Lanzhou Petrochemical Institute Of China Petrochemical Corp; Petrochina Lanzhou Petrochemical Co
Priority date: 2000-06-09
Filing date: 2000-06-09
Publication date: 2004-02-18
Anticipated expiration: 2020-06-09
Also published as: CN1275534A

Abstract

The present invention provides a waste alkali processing technique which has the advantages of low processing equipment investment and low processing cost. The present invention can use waste to make waste, comprehensively utilize reaction auxiliary products, and solves the problems of large investment and serious secondary pollution. The present invention comprises the specific method: pulverized coal ash and waste alkali are mixed, if necessary, metal oxide can be added, and the pulverized coal ash and the waste alkali can sufficiently react by heating. The present invention can greatly reduce the alkalinity of the waste alkali, convert toxic and harmful substances, such as sulfide, sodium carbonate, sodium hydroxide, etc., and enhance the effective silicone content in reaction products. Products after reacting can be used for preparing highly efficient compound fertilizer which contains silicon.

Description

A kind of spent lye treatment method

Technical field

The present invention relates to the treatment process of a kind of processing method of industrial waste water, particularly waste lye.

Background technology

Waste lye mainly comes from paper mill (using the alkali lye mashing off), refinery (with NaOH solution absorption H ₂S gas or the sulfide of washing in the oil product), ethylene plant (with the sulfide in the alkali liquid washing splitting gas), generally contain a large amount of NaOH, Na in the waste lye ₂Poisonous, objectionable impurities such as S, NaHS.

The hydrochloric acid neutralisation is generally adopted in the processing of waste lye in the prior art, NaOH is converted into NaCl, S ^2-Be converted into H ₂S burning or recovery, this method investment is big, processing cost is high, equipment corrosion is serious, is difficult to normal the operation in each application units; The catalytic wet oxidation of employing method is also arranged with S ^2-Be oxidized to SO ₄ ^2-Thereby, reach harmless treatment, but this method needs high temperature, high pressure, operational danger is big, processing cost is high, also is not used widely; Also have such as from technology such as alkali lye reclaim(ed) sulfuric acid sodium, but because these technology or produce secondary pollution, or invest hugely, be not suitable for industrial applications.

Flyash approximately contains 50%SiO ₂, 20%Al ₂O ₃, also contain 5%Fe ₂O ₃, 3%MgO, 6%CaO, 2%K ₂Materials such as O, the specific surface area of flyash is very big, has good absorption and coagulation performance, according to " total utilization of PCA " 1996; (4): bibliographical informations such as 33-35, there is producer to utilize absorption, the coagulation performance of flyash to remove the dyeing waste water color, handle fluoride waste, effect is good.

Summary of the invention

The spent lye treatment technology that the object of the present invention is to provide that the investment of a kind of treatment unit is low, processing cost is low, the treatment of wastes with processes of wastes against one another, reacted product can fully utilize has changed and has invested huge or the state of the art that secondary pollution is serious.

For realizing the object of the invention, the concrete grammar of employing is:

At first flyash is mixed with waste lye, stir, this step makes flyash adsorb waste lye in a large number, it is fully reacted mixture heating up then, when the basicity in the waste lye reduces significantly, sulfide, yellow soda ash, sodium hydroxide etc. are poisonous, objectionable impurities is changed into nontoxic, innoxious substance, and improve water-soluble silicon content in the reaction product.The product that reaction finishes can be used for preparation and efficiently contains silicon composite fertilizer.

Waste lye described in the present invention can be refinery desulfurization waste lye or ethene desulfurization alkali lye or paper mill waste lye or the like.

Flyash has very big specific surface area, but its 50%SiO ₂In have only 0.005% to be effective silicon that plant can absorb, i.e. water-soluble silicon; Generally contain a large amount of NaOH, Na in the waste lye ₂Material such as S, NaHS; The add-on of flyash depends on the kind and the contained material of waste lye.Invention mechanism of the present invention is: utilize the huge specific surface area of flyash at first to adsorb in the waste lye _NaOH, Na ₂Material such as S, NaHS; Secondly the alkaloids that has been adsorbed can activate the metal oxide formation active center in the part flyash, and it can be used as S ^2-To SO ₄ ^2-The catalysts that transforms, reaction has also reduced the basicity in the mixture when removing sulfide, and Heating temperature generally is no more than 350 ℃.

In order to raise the efficiency, the present invention also can add the metal oxide such as the Mn that can participate in reaction or can be used as catalyzer targetedly to different waste lyes in the mixture of flyash and waste lye, Fe, and Cu, the metal oxide of K etc. is with fast reaction speed.Because reaction product can be used for preparation at last and contains silicon composite fertilizer, so avoid using heavy metal.

After waste lye adopted spent lye treatment method of the present invention to handle, sulfide can remove more than 80%; Basicity can remove more than 50%; More than O.45% available silicon content can reach, compare its available silicon content with flyash and improved about 100 times, reached and utilized flyash to handle waste lye, reaction product can prepare the purpose that contains silicon composite fertilizer again.Spent lye treatment method of the present invention has advantages such as the treatment unit investment is low, processing cost is low, good in economic efficiency.

Embodiment

Embodiment 1:

Ethylene production factory waste lye harmful substance contents: wt%

NaOH Na ₂S NaHS Na ₂CO ₃NaHCO ₃Organism

2.3 1.2 0.9 7.1 5.6 0.05

With 300 gram flyash, 100ml ethene desulfurization waste lye thorough mixing, mixture is added reactor, heating is 150 minutes under 120 ℃ of conditions.After reaction finished, sulfide had reduced by 87% in the mixture, basicity has reduced by 55%, water-soluble silicon content has reached 0.65%.The water-soluble silicon Determination on content adopts the molybdenum yellow light-intensity method.

Embodiment 2

Paper mill waste lye harmful substance contents:

PH solid substance wt% COD/mgL ^-1SS/mgL ^-1

11.5 12.6 80500 15342

With 300 gram flyash, 50ml paper mill waste lye thorough mixing, add 0.25 gram manganese oxide; Mixture is added reactor, and heating is 66 minutes under 65 ℃ of conditions.After reaction finished, sulfide had reduced by 82% in the mixture, basicity has reduced by 50%, water-soluble silicon content has reached 0.55%.

Embodiment 3

Refinery waste lye harmful substance contents:

NaOH/g·L ^-1 RSNa/g·L ^-1 Na ₂S/g·L ^-1 R ₂S/g·L ^-1

0.05 34.68 12.63 6.01

With 300 gram flyash, 150ml refinery desulfurization waste lye thorough mixing, add 0.25 gram Z 250,0.15 gram cupric oxide; Mixture is added reactor, and heating is 150 minutes under 150 ℃ of conditions.After reaction finished, sulfide had reduced by 81% in the mixture, basicity has reduced by 58%, water-soluble silicon content has reached 0.75%.

Embodiment 4

With the ethene desulfurization waste lye thorough mixing among 300 gram flyash, the 200ml embodiment 1, add 0.15 gram potassium oxide, the manganese oxide of 0.25 gram; Mixture is added reactor, and heating is 150 minutes under 120 ℃ of conditions.After reaction finished, sulfide had reduced by 89% in the mixture, basicity has reduced by 60%, water-soluble silicon content has reached 0.45%.

Embodiment 5

With the refinery waste lye thorough mixing among 300 gram flyash, the 250ml embodiment 3, add 0.35 gram ferric oxide; Mixture is added reactor, and heating is 180 minutes under 110 ℃ of conditions.After reaction finished, sulfide had reduced by 90% in the mixture, basicity has reduced by 65%, water-soluble silicon content has reached 0.60%.

Claims

1. spent lye treatment method, it is characterized in that: flyash is mixed with waste lye, stir, then with mixture heating up to 65～150 ℃, it is fully reacted, when the basicity in the waste lye reduced significantly, sulfide, yellow soda ash, sodium hydroxide were poisonous, objectionable impurities is changed into nontoxic, innoxious substance, and improved water-soluble silicon content in the reaction product.

2. spent lye treatment method, it is characterized in that: flyash is mixed with waste lye, stir, add the metal oxide that can participate in reaction or can be used as catalyzer, it is fully reacted mixture heating up then, when the basicity in the waste lye reduced significantly, sulfide, yellow soda ash, sodium hydroxide were poisonous, objectionable impurities is changed into nontoxic, innoxious substance, and improved water-soluble silicon content in the reaction product.

3. spent lye treatment method according to claim 2 is characterized in that described metal oxide is Mn, Fe, Cu, the oxide compound of K.