CN103058149A - Method for producing sulfuric acid by using gypsum - Google Patents

Abstract

The invention discloses a method for producing sulfuric acid by using gypsum. The method comprises the following steps of: (1) putting gypsum powder into a roasting device, heating the temperature to a range between 700 and 850 DEG C, and continually introducing methane gas into the roasting device to react with the gypsum, wherein the molar ratio of the methane gas to the gypsum is 1: (4-4.2); and (2) sequentially introducing the mixed gas of generated sulfur dioxide, carbon dioxide and water vapor into a dust remover and a drying pipeline, then introducing the mixed gas to a condensation pipe of less than 10 DEG C below zero, introducing the rest mixed gas into a sodium hydroxide solution of which the concentration is more than or equal to 50 weight percent, newly introducing the mixed gas into the roasting device, introducing the sulfur dioxide liquefied through the condensation pipe into an oxidation chamber containing a vanadium pentoxide catalyst to convert the sulfur dioxide into sulfur trioxide at the temperature between 500 and 900 DEG C, finally introducing the generated sulfur trioxide into concentrated sulfuric acid of which the concentration is more than or equal to 75 percent, and thus obtaining the sulfuric acid. The roasting temperature in the method is lower than that in other methods for preparing the sulfuric acid by using calcium sulfate, and the method is low in energy consumption and can reduce the production cost.

Description

A kind of method of producing sulfate acid from gypsum

Technical field

The present invention relates to a kind of method of producing sulfuric acid, especially relate to a kind of method of producing sulfate acid from gypsum.

Background technology

China is the country of a sulphur resource shortage, and annual sulfuric acid consumption is quite large.Simultaneously, the sulfur-bearing waste that produces in some industrial production of China is also seriously restricting the development of producing.

China's gypsum reserves are abundant, and explored about 1,000 hundred million tons, the sulfur-bearing waste residue when adding products such as producing phosphoric acid, especially a surprising data.Therefore, can effectively solve the problem of China's sulphur resource shortage take gypsum as waste sulfuric acid.

CN102838153A discloses a kind of gypsum on December 26th, 2012 and has decomposed the method for producing sulfuric acid and calcium oxide, and the method makes sulfuric acid take gypsum and coke as raw material through steps such as preheating, calcining and decomposing.The defective of its existence is: (1) raw material gypsum and coke are solid, and solid-solid reaction speed is relatively slow, gypsum to turn interest rate also relatively low; (2) the calcining and decomposing temperature is higher, is specially 900-1250 ℃, and energy consumption is higher, and production cost is higher; (3) for fear of the generation of side reaction, need to be weak oxide atmosphere, troublesome poeration in the control stove.

Summary of the invention

Technical problem to be solved by this invention is, provides a kind of more effective, and energy consumption is lower, the method for the producing sulfate acid from gypsum that manufacturing cost is lower.

The technical scheme that the present invention solves its technical problem employing is: a kind of method of producing sulfate acid from gypsum may further comprise the steps:

(1) gypsum powder is placed calciner, be warming up to 700-850 ℃, constantly pass into methane gas in the roast device again and gypsum reacts, the mol ratio of described methane gas and gypsum is 1:(4-4.2), reaction 25-50min, generating sulfurous gas, carbonic acid gas, water vapour and main component is the solid of calcium oxide;

(2) with the mixed gas of the sulfurous gas of step (1) gained, carbonic acid gas, water vapour first successively by fly-ash separator and be full of CaCl ₂The drying duct of powder, to remove dust, water vapour wherein, then mixed gas is passed into temperature and be lower than-10 ℃ prolong, remaining mixed gas passes into the roast device in the step (1) after by concentration 〉=50wt% sodium hydroxide solution again, sulfurous gas passes into the oxidizing chamber that contains the Vanadium Pentoxide catalyzer after prolong liquefaction, under 500-900 ℃, be converted into sulphur trioxide, at last the sulphur trioxide that generates led to the vitriol oil of concentration 〉=75wt%, to make sulfuric acid;

(3) be that the solid product of calcium oxide is for the production of cement and lime with step (1) gained main component.

Further, in the step (1), used gypsum can be the plaster of paris (plaster of paris powder of preferred purity 〉=98wt%), also can be the waste take calcium sulfate as main component that produces in the industrial production.

Reaction equation of the present invention is:

，

，

。

The present invention utilizes methane gas and calcium sulphate solid generation gas-solid reaction, fully contact between the reactant, and reaction is easy to occur, and can improve the transformation efficiency to 80% of calcium sulfate, and the sulfur dioxide concentration that is created in the calciner is high; Simultaneously, maturing temperature of the present invention is lower than other prepares sulfuric acid with calcium sulfate the maturing temperature of method, and energy consumption is low, can reduce production costs.

In addition, but raw materials used methane synthetic obtain, also can obtain by methane-generating pit.After the reaction, can not generate the gas of contaminate environment.Methane is nontoxic gas, in a small amount of situation of leaking, the workman is poisoned.

Particularly importantly, the present invention can be adapted to produce in the industrial production take calcium sulfate as main waste, can in reducing Chemical Manufacture, turn waste into wealth in the waste pollution, bring economic interests to enterprise.

Embodiment

The invention will be further described below in conjunction with embodiment.

Embodiment 1

Present embodiment may further comprise the steps:

(1) be that the plaster of paris powder of 98.5wt% places calciner with purity, be warming up to 800 ℃, constantly pass into methane gas in the roast device again and gypsum reacts, the mol ratio of described methane gas and gypsum is 1:4.05, reaction 25min, generating sulfurous gas, carbonic acid gas, water vapour and main component is the solid of calcium oxide;

(2) with the mixed gas of step (1) gained sulfurous gas, carbonic acid gas, water vapour first successively by fly-ash separator and be full of CaCl ₂The drying duct of powder, to remove dust, water vapour wherein, then mixed gas is passed into temperature and be-15 ℃ prolong, remaining mixed gas is the roast device that again passes into behind the 55wt% sodium hydroxide solution in the step (1) by concentration, sulfurous gas passes into the oxidizing chamber that contains the Vanadium Pentoxide catalyzer after prolong liquefaction, under 850 ℃, be converted into sulphur trioxide, at last the sulphur trioxide that generates led to the vitriol oil of concentration 80wt%, to make sulfuric acid;

(3) be that the solid product of calcium oxide is for the production of cement and lime with step (1) gained main component.

Embodiment 2

Present embodiment may further comprise the steps:

(1) places calciner with what produce in the industrial production take calcium sulfate as main waste, be warming up to 850 ℃, constantly pass into methane gas in the roast device again and gypsum reacts, the mol ratio of described methane gas and gypsum is 1:4.2, reaction 40min, generating sulfurous gas, carbonic acid gas, water vapour and main component is the solid of calcium oxide;

(2) with the mixed gas of step (1) gained sulfurous gas, carbonic acid gas, water vapour first successively by fly-ash separator and be full of CaCl ₂The drying duct of powder, to remove dust, water vapour wherein, then mixed gas is passed into temperature and be-20 ℃ prolong, remaining mixed gas passes into the roast device in the step (1) after by concentration 60wt% sodium hydroxide solution again, sulfurous gas passes into the oxidizing chamber that contains the Vanadium Pentoxide catalyzer after prolong liquefaction, be converted into sulphur trioxide under 800 ℃, at last the sulphur trioxide that generates being led to concentration is the vitriol oil of 75wt%, to make sulfuric acid;

(3) be that the solid product of calcium oxide is for the production of cement and lime with step (1) gained main component.

Claims (2)

1. the method for a producing sulfate acid from gypsum is characterized in that, may further comprise the steps:

(1) gypsum powder is placed calciner, be warming up to 700-850 ℃, constantly pass into methane gas in the roast device again and gypsum reacts, the mol ratio of described methane gas and gypsum is 1:(4-4.2), reaction 25-50min, generating sulfurous gas, carbonic acid gas, water vapour and main component is the solid of calcium oxide;

(2) with the mixed gas of the sulfurous gas of step (1) gained, carbonic acid gas, water vapour first successively by fly-ash separator and be full of CaCl ₂The drying duct of powder, to remove dust, water vapour wherein, then mixed gas is passed into temperature and be lower than-10 ℃ prolong, remaining mixed gas passes into the roast device in the step (1) after by concentration 〉=50wt% sodium hydroxide solution again, sulfurous gas passes into the oxidizing chamber that contains the Vanadium Pentoxide catalyzer after prolong liquefaction, under 500-900 ℃, be converted into sulphur trioxide, at last the sulphur trioxide that generates led to the vitriol oil of concentration 〉=75wt%, to make sulfuric acid;

(3) be that the solid product of calcium oxide is for the production of cement and lime with step (1) gained main component.

2. the method for producing sulfate acid from gypsum according to claim 1 is characterized in that, in the step (1), used gypsum is the waste take calcium sulfate as main component that produces in the plaster of paris or the industrial production.