A memoir on British resources of sands suitable for glass-making .. by unknow

Author:unknow
Language: eng
Format: epub
Tags: Glass manufacture
Publisher: London, [etc.] : Longmans
Published: 1916-03-25T05:00:00+00:00

0-5 0-25

► Grade Sizes (diameter in Millimetres)

Fig. 10.— Mechanical Analyses of G-lass-Sands : British.

lOO/i;

90

80

i,70

i,60

5 50.

.S 40

§30

20 .

10

1-0

0-S 0-25

► Grade Sizes (diameter irt l^illimetres)

successive consignments conform to the highest standard of purity met with, and variability is abhorred by glass-makers. The whiteness and purity may be connected with the peaty bands. The colour is good, the best Aylesbuiy sand being better than Belgian, and selected samples being equal to Fontainebleau sand. Washing does not improve the colour of the best sand to any extent, but a second-quality sand, washed free from limonitic and clayey pellets (in rotary washing-plant), is also supplied. The latter sand is pale grey, but reddens slightly on burning, whereS,s the former shows little or ns change. The chemical composition is as follows:—

Washed sand Best sand. as delivered.

SiOj 99-80 per cent. 99-39 per cent.

Alfl, -32 -48

Fe^Oj -03 -02

Loss on ignition -22 -13

Total 100-37 per cent. 100-02 per cent.

The evenness of grade is a marked feature, the sand in this respect very closely resembUng Fontainebleau (see Plate III, figs. 1 & 3). The mechanical composition is as follows :—

>0-5 mm., few grains only; >0-a5 & <0-5, 78-3 »/o i >0-l & <0-a5,15-0 % ; >0-01 & <0-l, 5-8 »/„ ; <0-01,0-9 %• Total sand-grade, >0-l, 93-3 "/o-

r^ D B^ F^ G_ C-E -|

Ltr.' 78-3' 15-0' 5-8' 0-9' 93-3'J

The detrital mineral suite is very marked and is characteristic of the Lower Greensand throughout England. Heavy minerals are fairly abundant (0-2 to 0-3 mm. diameter), and the residue consists almost entirely of coarse, angular kyanite, staurolite, and brown and blue tourmaline, together with iron ores (magnetite, limonite, and altered ihnenite), zircon, rutile, etc.

The sands, after being carted to Hartwell Siding near Aylesbury Station (G. C. Eailway), were put on trucks, before the war, at 7s. 6d. per ton. At the time of writing the price is 10s. This is rather high, and freight charges increase it to about 15«. or 17s. 6d. by the time it reacljes a glass-making district as far distant as London or Yorkshire.

The estimated quantity available in the area is 2 million tons *.

" Leighton Buzzard " Sand. Worked by (1) Mr. Joseph Arnold, (2) Mr. George Garside, (3) Mr. Gregory Harris. Maps. —Geological: Old Series, 1-inch, Sheet 46 N.W.

6-inch, Bedfordshire, Sheet 28N.E. Situation.—Lat. 51° 56' 15" to 51° 57' 10", Lonff. 0° 38' 20" to 0° 39' 10" W.

* In each case the estimate of the resources is by the writer, and is to be taken as well within the upper limit.

The sand is worked over a large area north and north-east of Leighton Buzzard. Numerous quarries and old workings oecui-(Mile Tree, Shenley Hill, Stone Lane, Chance's Quarry, etc.).

Formation. —Lower Greensand.

Bescription. —The deposits are worked for a variety of purposes, glass-making being subordinate.

Both chemical and mechanical compositions vary considerably. The coarse sands are supplied for water-filtration plant, concrete-making, grinding, etc. The highly ferruginous sand is used for building, and most of the pale-coloured medium-grained sands are worked and washed by the rotaiy method for foundry purposes, particularly in connexion with steel-work.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.