PAPERmaking! Vol5 Nr2 2019

3

M.A.W. Gaber / Egyptian Journal of Petroleum xxx (2017) xxx–xxx

a- Outcrop of limestone

b- Quarry of chalky limestone

c- Cutting of limestone building blocks

d- location of limestone quarry's

Fig. 3. Field photos showing outcrop and quarry of pure limestone at El Minia East Nile Valley.

4.1. Specific gravity

Table 2 Properties standard limits of Kaolin, PCC and GCC fillers used in paper manufacture.

The representative samples of limestone measured according to [13] and the results are ranging from 2.6 to 2.7 g/cm 3 as indicated in Table 4. , as per standard the low specific gravity is preferred for paper manufacture.

Property

Kaolin

PCC

GCC

Brightness Particle size

80 85%

90–97%

> 90–96%

2 l m

Manufacture fine high at high load

Required grinding

Opacity

Excellent

Moderate at high load

4.2. Oil absorption

Loading level

20–30%

Limited to 20% 20–30%

The test were carried out using linseed oil mixed with carbonate powder and the specific paste obtained at the ratio of oil quantity is ranging from 32 to 36 g/100 g (g of oil/g of powder), as per [14,15].

Sheet strength Good

Moderate

Excellent

Bulking

Moderate

Good High

Good

Absorption Chemical

Low Inert

Low

Unstable in acid

Unstable in acid

reactivity

4.3. Moisture content

Flexibility

Filler/Coating Mainly filler

Alkaline - filler/coating

Processing

Extensive

Energy extensive

Grinding/sizing

The moisture content of limestone powder was determined at 105  C and the results ranging from 0.05 to 0.07% and considered low percentage moisture according to [16].

Availability

Restricted

Satellite plants Geologically plentiful

Price

Low (N. America)

Based on cost

Low (Europe)

4.4. Particle size

Calcium carbonate pigments for paper making occurs in the form of a fine powder or lumps by using crushing equipment’s was ground to very fine grains. The recommended size of lime- stone powder pigment shall be in limit of 2–10 l m as shown in (Fig. 4). The vast majority of particles are much smaller in size than 10 m m; there is some evidence that a mixture of particle sizes is desirable for increased durability, reduced absorption and reduced permeability of the film, also the particle size distribution graph (Fig. 5), showing that the 80% of analyzed sample is less than 10 l m in size.

Table 3 Brightness of El Minia calcium carbonate.

Limestone samples Brightness (z-direction) Sample 1 91 Sample 2 93.5 Sample 3 90.5 Sample 4 91.5

Please cite this article in press as: M.A.W. Gaber, Characterizations of El Minia limestone for manufacturing paper filler and coating, Egypt. J. Petrol. (2017), http://dx.doi.org/10.1016/j.ejpe.2017.07.007

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