Skip to content

Posts tagged ‘alumina’

3
Mar

activated alumina TiO2-Al2O3 Catalyst carrier and catalyst

The activated alumina TiO2-Al2O3 Catalyst carrier and catalyst product can be used as sulphur-recovering catalyst as well as catalyst carrier such as metuane catalyst,hydrogenating catalyst and etc.

Specification of TiO2-Al2O3 Catalyst carrier and catalyst

 

Index

Specificatiom

Al2O3 %

> 80

TiO2 %

> 6

Sphere Size mm

¢2-3 ¢3-5 ¢4-6

Appearance

White Sphere

Bulk Density g/cm3

0.68–0.75

Crush Resistance N/sphere

60–180

Surface Area m2/g

>200series >300series

Pore Volume cm3/g

0.38series 0.55series

Packed Columns Tower Packing Supplier

2
Mar

Basic Terminalogy Used in Alumina Refinery

Hi Friends,

In the present post, I thought of explaining the basic terminalogy used during design, engineering and successful operation of Alumina refinery. Though, different alumina designers and manufacturers use different terminalogy for expressing the same paramter which has exactly the same physical significance. It is very simple to understand those confusing terminalogies used by different companies as described here under-

Solids Concentration in Slurry:
Solids (Bauxite, Hydrate or Residue) concentration in aluminate liquor are analysed either as grams per litre (gpl) or percentage solids on weight basis (% solids). Grams of solids present in every litre of respective slurry is expressed as gpl solids in slurry. Where as grams of solids present in 100 grams of slurry sample is termed as % solids (w/w). For example, ground Bauxite slurry contains about 50 to 55% solids (w/w) where as the solid consistency in residue discharged from plant to Residue pond varies from 55% to 65% adopting dry stacking technology.
Liquor Concentration:
Terminalogy used for caustic concentration of  various streams of aluminate liquor in Alumina refinery  are expressed as follows-
  • GPL Soluble Caustic:- Soluble caustic is also termed as Free caustic expressed as Na2CO3 ( or as Na2O) equivalent to hydroxyl ions (OH- ions) present per litre of liquor.
  • GPL Total Soda:-  The total sodium carbonate corresponding to total caustic present in the form of hydroxide, aluminate and carbonate in liquor is termed as gpl total soda or total titratable soda (TTS).
Higher concentration plants yield improved productivity but pose problems in handling due to higher viscosity. Hence plant is operated at optimised concentration profile.
Plant Causticity:
The ratio of soluble caustic to total titratable soda present in Spent liquor of Alumina refinery is termed as Plant causticity expressed in percentage.
Thus Plant Causticity = (gpl soluble caustic / gpl total soda) x 100 %.
or, Plant Causticity = (gpl Na2O soluble / gpl Na2O total) x 100 %.
Plant causticity is the indicative measure of purity level of plant liquor. Plant causticity varies from 80% to 85% depending on the impurity level in liquor. Higher plant causticity results in improved plant efficiencies.
Alumina to Caustic Ratio:
The ratio of gpl Al2O3 to gpl soluble in any stream of Alumina refinery is known as A/C Ratio. This same ratio of alumina to soluble caustic is expressed by different alumina refineries differently as outlined here under-
Thus,  A/C Ratio = (gpl Al2O3 / gpl Na2CO3 as Free caustic)
Some plants use terms RP and MR which have different values for similar applications in the plant.
  • RP = (gpl Al2O3) / (gpl Na2O as Free caustic).
  • Molar Ratio (MR) = (Moles of Na2O as Free caustic) / (Moles of Alumina)
  • MR  = (gpl Na2O as Free caustic x 102) / (gpl Al2O3 x 62)
  • MR  = (1.645 x gpl Na2O as Free caustic) / (gpl Al2O3)
  Therefore,  Molar Ratio = 1.645 / RP
Higher A/C ratio in digestion and precipitation feed stages are preferred for achieving higher productivity but the lower A/C ratio in spent liquor is desirable.
Trust, I have presented the basic terminalogy in simplified fashion.
Your views / remarks on above shall be welcomed.
Regards.
Kunwar Rajendra

ALUMINA TECHNOLOGY

2
Mar

activated alumina as special absorbers for hydrogen peroxide

The activated alumina as special absorbers for hydrogen peroxide product is used for reclaiming degradation product in the working fluid in hydrogen peroxide production by Anthraquinone Method. Especially, in the plants of palladium catalyst and three-component nickel catalyst, there is no other better method for degradation except activated alumina, this kind of special absorbers, which is indispensable to hydrogen peroxide production.

Many tests, valuations and application in hydrogen peroxide can show that special absorbers for hydrogen peroxide products, compared with other similar products, is the perfect one at home at present, also has many good properties such as, less floating powder, low abrasion quantity, big specific surface area, good degradability, long life period.

 

Specification of special absorbers for hydrogen peroxide

 

SPECIFICATION

INDEX

CRYSTALLINE PHASE

γ-Al2O3

SPHERE SIZE  (mm)

7-14MUSH

Φ3-5、Φ4-6 、Φ5-7

APPEARANCE

WHITE SPHERE

BULK DENSITY(g/cm³)

0.68-0.75

CRUSH RESIS TANCE  (N)

>50

SURFACE AREA  (m²/g)

200-260

PORE VOLUME  (cm³/g)

0.40-0.46

MACROPOROSITY  (>750A)

0.14

COEFFICIENT OF WATER ABSORPTION

>50

Packed Columns Tower Packing Supplier

2
Mar

activated alumina catalyst carrier for sulfate resisting conversion

The activated alumina catalyst carrier for sulfate resisting conversion is often used as sulfate-resistant conversion catalyst carrier in chemical fertilizer.

 

Specification of activated alumina catalyst carrier for sulfate resisting conversion

 

Index

Specificatiom

Crystalline Phase

r—Al2O3

Sphere Size mm

¢2-3 ¢3-5 ¢4-6

Appearance

White Sphere

Bulk Density g/cm3

0.53–0.65

Crush Resistance N/sphere

> 200

Surface Area m2/g

60–180

Pore Volume cm3/g

> 0.45

Coefficient Of Water Absorption %

> 60

Packed Columns Tower Packing Supplier