CN102502861B - Process for synthesizing iron oxide brown - Google Patents

Abstract

The invention discloses a process for synthesizing iron oxide brown, comprising the following steps of: feeding a ferrous sulfate solution into a reaction kettle; slowly adding caustic soda liquid in three times; then heating to a temperature in the reaction kettle of 75-78 DEG C and incubating for 50-70 min; adding water to dilute mixed slurry until solid content of the mixed slurry is 8-10%; slowly adding sodium nitrite into the reaction kettle and introducing oxygen simultaneously; then turning on spraying equipment to sufficiently mix the slurry, oxygen gas and NO which is generated in a reaction process; continuously sampling and comparing a sample with a standard sample in the reaction process; stopping the reaction when the colored light of a product is similar to the yellowish-brown or reddish brown colored light of standard sample; and carrying out plate pressure filtration, washing, drying and crashing the taken-out slurry so as to obtain the product. The iron oxide brown produced by the invention includes brownish red iron oxide brown and brownish yellow iron oxide brown. Compared with the traditional method for preparing the iron oxide brown by physically mixing iron oxide red, iron oxide black and iron oxide yellow, the iron oxide brown produced by the invention is stable in quality and pure in colored light, the synthesis method is simple and the operation is convenient.

Description

The synthesis technique of a kind of cologne earth

Technical field

The present invention relates to the production method of a kind of cologne earth, is exactly the synthesis technique of a kind of cologne earth.

Background technology

The molecular formula of cologne earth is (Fe ₂o ₃+ FeO) nH ₂o, it is a kind of brown ceramic powder, and water insoluble, alcohol, ether, be dissolved in hot strong acid, and tinting strength and opacifying power are very high simultaneously, and photostabilization, alkali resistance are good, anhydrous oozing property and oozing property of oil.Its form and aspect are with the difference of technique, are divided into yellowish-brown, reddish brown, black palm fibre etc.It is widely used in painted and coating, building, rubber, plastics etc. painted of the goods such as paint, ink, plastics, shoe powder.

Traditional cologne earth is that quality product is unstable by forming by iron oxide black, iron oxide yellow and three kinds of pigment physics blendings of iron oxide red, has the deficiency of form and aspect inequality, so directly synthesize the product that cologne earth product is better than physical mixed in performance

Summary of the invention

The object of the invention is for a kind of color is provided is yellowish-brown and reddish-brown, has good tinting strength, form and aspect and stability, prepares the synthesis technique of easy cologne earth simultaneously.

Technical scheme of the present invention is as follows:

A synthesis technique for cologne earth, is characterized in that: comprise the following steps:

(1), in reactor, add copperas solution, then according to mass ratio NaOH: FeSO ₄slowly add liquid caustic soda at=3: 1～0.8, liquid caustic soda divides three times and adds, every minor tick 28-32 minute, again reactor temperature is warmed up to 75-78 ℃, temperature-rise period need be controlled temperature and be undertaken by 5 ℃ of intensifications per hour, reaches 75 ℃ stop above heating up to temperature, is incubated after 50-70 minute, thin up mixed slurry to solid content is 8-10%;

(2), in the ratio of product input 45-50KG per ton, in reactor, slowly add Sodium Nitrite, Sodium Nitrite divides three times and adds, every minor tick 30-32 minute, pass into oxygen simultaneously, the pressure that passes into of oxygen is 10-13cm water column, then opens sprinkling equipment the NO of the generation in slip, oxygen and reaction process is fully mixed;

(3), in reaction process, constantly sampling and standard model comparison, the standard model coloured light of product coloured light and yellowish-brown or reddish-brown coloured light is similar to stopped reaction afterwards, the slip of taking-up is obtained after filter press, washing, oven dry, fragmentation to product.

The preparation method of described iron oxide brown, is characterized in that: described copperas solution be containing assorted copperas solution with method for hydrolysis remove titanium impurity, again water to regulate concentration be after 33-37%; Described liquid caustic soda concentration is 30-45%.

Principle equation of the present invention:

FeSO ₄+2NaOH＝Fe(OH) ₂↓+Na ₂SO ₄；

NaNO ₂+Fe(OH) ₂+H ₂O＝Fe(OH) ₃+NaOH+NO；

2NO+O ₂＝2NO ₂；

3NO ₂+H ₂O＝2HNO ₃+NO；

HNO ₃+3Fe(OH) ₂+H ₂O＝3Fe(OH) ₃+NO；

2Fe(OH) ₃＝Fe ₂O ₃+3H ₂O。

Beneficial effect of the present invention is:

The cologne earth that the present invention produces is reddish brown and pale brown two kinds, compares with the cologne earth of iron oxide red, iron oxide black, iron oxide yellow physics blending one-tenth tradition for, and the cologne earth steady quality of the inventive method production, coloured light is pure and synthetic method is simple, easy to operate.

Embodiment

A synthesis technique for cologne earth, is characterized in that: comprise the following steps:

(1), in reactor, add copperas solution, then according to mass ratio NaOH: FeSO ₄slowly add liquid caustic soda at=3: 1～0.8, liquid caustic soda divides three times and adds, every minor tick 28-32 minute, again reactor temperature is warmed up to 75-78 ℃, temperature-rise period need be controlled temperature and be undertaken by 5 ℃ of intensifications per hour, reaches 75 ℃ stop above heating up to temperature, is incubated after 50-70 minute, thin up mixed slurry to solid content is 8-10%;

(2), in the ratio of product input 45-50KG per ton, in reactor, slowly add Sodium Nitrite, Sodium Nitrite divides three times and adds, every minor tick 30-32 minute, pass into oxygen simultaneously, the pressure that passes into of oxygen is 10-13em water column, then opens sprinkling equipment the NO of the generation in slip, oxygen and reaction process is fully mixed;

(3), in reaction process, constantly sampling and standard model comparison, the standard model coloured light of product coloured light and yellowish-brown or reddish-brown coloured light is similar to stopped reaction afterwards, the slip of taking-up is obtained after filter press, washing, oven dry, fragmentation to product.

The preparation method of described iron oxide brown, is characterized in that: described copperas solution be containing assorted copperas solution with method for hydrolysis remove titanium impurity, again water to regulate concentration be after 33-37%; Described liquid caustic soda concentration is 30-45%.

The detected result table of product of the present invention

The cologne earth that the present invention produces is reddish brown and pale brown two kinds, compares with the cologne earth of iron oxide red, iron oxide black, iron oxide yellow physics blending one-tenth tradition for, and the cologne earth steady quality of the inventive method production, coloured light is pure and synthetic method is simple, easy to operate.

Claims (1)

1. a synthesis technique for cologne earth, is characterized in that: comprise the following steps:

(1), in reactor, add copperas solution, then according to mass ratio NaOH:FeSO ₄=3:1～0.8 slowly adds liquid caustic soda, liquid caustic soda divides three times and adds, every minor tick 28-32 minute, again reactor temperature is warmed up to 75-78 ℃, temperature-rise period need be controlled temperature and be undertaken by 5 ℃ of intensifications per hour, reaches 75 ℃ stop above heating up to temperature, is incubated after 50-70 minute, thin up mixed slurry to solid content is 8-10%, described copperas solution be containing assorted copperas solution with method for hydrolysis remove titanium impurity, again water to regulate concentration be after 33-37%; Described liquid caustic soda concentration is 30-45%;

(2), in the ratio of product input 45-50Kg per ton, in reactor, slowly add Sodium Nitrite, Sodium Nitrite divides three times and adds, every minor tick 30-32 minute, pass into oxygen simultaneously, the pressure that passes into of oxygen is 10-13cm water column, then opens sprinkling equipment the NO of the generation in slip, oxygen and reaction process is fully mixed;

(3), in reaction process, constantly sampling and standard model comparison, the standard model coloured light of product coloured light and yellowish-brown or reddish-brown coloured light is similar to stopped reaction afterwards, the slip of taking-up is obtained after filter press, washing, oven dry, fragmentation to product.