C o n s titu tio n of P o r t la n d c e m e n t. I I . K . Ko y a n a g i, S . Ka t o h, and T . Su d o i i (Zement, 1938, 27, 363—367; cf. B., 1938, 59).—A high- A120 3 (10-57%) P ortland cement clinker was ground an d fractionated centrifugally as previously. Although Bogue’s method of calculation indicated no 3C a0,Si02 (I) in th e heaviest fraction, X -ray photographs showed a n appreciable am ount. The lattice of th e 3Ca0,Al20 3 (II) in th e clinker was smaller th an th a t of the pure mineral. Working w ith pure m aterials, mixed crystals were formed on adding 4C a0,Fe20 3,Al20 3 to pure (I), with enlargem ent of the lattice;
addition of (I) to (II) caused shrinkage of the lattice, th e max. am ount of which agreed w ith th a t of (II)
in cement. G. H. C.
E ffe c t of g la s s c o n te n t o n h e a t of h y d r a tio n of P o r t l a n d c e m e n t. W. L e r c h (J. Res. N at. Bur.
Stand., 1938, 2 1 , 235— 240).—The heats of hydration (AH) of a no. of cements with different glass contents (c) have been determ ined by the heat of dissolution m ethod. The heat evolved a t 7—28 days from mixing depends on th e cem ent composition and c, th e la tte r having a direct and also an indirect effect due to the variation of th e compound composition.
A fter 3 days AH is n o t consistently related to c, b u t a t 7—28 days AH increases w ith c. Causes of the variation of AH are discussed. A. J . E. W.
R e a c tio n s in th e s o lid s ta te a t h ig h t e m p e r a tu r e s . X V III. T ric a lc iu m s ilic a te , th e m o s t im p o r t a n t c o m p o n e n t of P o r t l a n d c e m e n t c lin k e r.
W. J a n d e r (Angew. Chem., 1938, 5 1 , 696—699).—- A review of published work. E . S. H.
R e la tio n of c o m p o s itio n s a n d h e a ts of d is s o l
u tio n of P o r t l a n d c e m e n t c lin k e r . H. I n s l e y , E . P.
F l i n t , E. S. N e w m a n , and J . A. S w e n s o n (J. Res.
N at. Bur. Stand., 1938, 2 1 , 355—365).—The results of chemical and microscopical analyses of commercial P ortland cement clinkers are compared. There are slight discrepancies in th e contents of 3C a0,S i02, 2C a0,S i02, 3CaO,AUC*3> an(i 4Ca0,Al20 3,Fe20 3 as determ ined by th e two m ethods. The cryst. com
pounds are n o t pure, b u t contain m aterials in solid solution. The observed heats of dissolution are in accord w ith those calc, from th e analyses, b u t th e assum ptions on which these calculations are based are
inexact. J . W. S.
Q u ic k -s e ttin g a n d h e a t-e v o lv in g c e m e n ts . V.
H y d ra u lic p r o p e r tie s of c e m e n ts . K . Ak iy a m a
(J. Soc. Chem. Ind . Jap a n , 1938, 4 1 , 249—250b;
cf. B., 1938, 516).—Cements having activ ity indices
< 1 and CaO content < 3 0 % are examined. High- aluminous cements are very slow in setting, bu t hardening properties improve w ith decrease of S i0 2 content. Quick-setting and heat-evolving cements of good quality are found w ithin the lim it of CaO
content < 3 0 % . A . T. P.
In flu e n ce of v a r io u s k in d s of c a lc iu m s u lp h a te o n p r o p e r tie s of c e m e n t. G. M u s s g n u g (Zement, 1938, 2 7 , 303—307).—The effect runs parallel to tho solubility of the CaS04. Ground into a rotary-kiln clinker of low A120 3 modulus, > 1 % of CaS04,0-5H20 (I) caused a flash set. Small am ounts of (I) m ade th e cement H 20-repellent. Norm al setting tim es were obtained with 2—6% of CaS04,2H20 (II). 1—3%
o f CaS04 (III) causes a quick set, 6% retards th e set to 4 hr. W ith (III) th e m ix requires more H 20 . Higher tem p. (30°) accelerates th e set slightly in all cases, especially w ith (II). The strength of dry- consistency m ortar increases to a m ax. a t 3—5%
(III) in each case and then decreases, b u t with plastic m ortar tho strength increases continuously w ith (III). High (III) content does n o t affect expansion during 28 days’ storage in H 20 , b u t shrinkage is decreased. 1% of (I) produces the same expansion in presence of 1-2% of free CaO as 3— 4% of (II) or
(III). G. H. C.
R a p id te s tin g of c e m e n t on th e s ite . D. De S im o n e (Ann. Lavori Pubbl., 1938, 7 6 , 558—562;
R oad Abs., 1938, 5 , No. 540).—An im pact-testing apparatus (the Zamboni ploximeter) for use in the rapid testing of cement and concrete is described.
Cylindrical test-pieces, m ade in a specified way, are fixed horizontally and subjected to im pact on one end from a ham m er swinging through a graduated arc, the angle of rebound of the ham m er being m easured and correlated w ith compressive strength. The same specimen m ay be tested a t different ages. T. W. P .
C o rro s io n of c o n c re te b y c h lo rid e s o lu tio n s . Y. M. Mo s k v x n (Kalii, 1938, No. 2, 23—27).—
Corrosion by NaCI, KC1, and MgCl2 solutions is discussed. A concrete containing <275 kg. of puzzuolana cement per cu. m. should be used. P o rt
land cement is n o t recommended. The H 20 -cem en t factor should be >0-65. Some practical suggestions, w ith illustrations, for laying th e cement are made.
D. G.
Im p ro v e m e n t of c o n c re te a d m ix tu r e s . L.
Pa l o t a s (Zement, 1936, 25, 305— 311; Chem.
Zentr., 1936, ii, 675).—Various empirical relationships between th e q u an tity of cement and~the grain size of adm ixed m aterial are reviewed and discussed.
H. J . E.
C o m p o sitio n a n d te s tin g of b itu m in o u s co n c r e te fille rs . H . Nu s s e l (Bitumen, 1936, 6, 99—
104; Chem. Zentr., 1936, ii, 3036).—Bituminous fillers should pour a t 200° and th e constituents should n o t separate on melting. D uctility a t low, stability a t high, tem p, and adhesion to stone are desirable qualities. Methods of testing and mixing are
summarised. A. H. C.
C a lc iu m s u lp h a te p la s te r s . W. R . Pi p p a r d
(Dept. Sci. Ind. Res., Building Res. Bull., 1938, No. 13, 16 pp.).—A new classification of the plasters is proposed, th e two m ain groups being th e hemi- hydrate and the anhyd. The former contains CaS04,0-5H20 , with and w ithout re ta rd e rs; th e latter is further subdivided into lightly burnt, m oderately burnt, hard bu rnt, and anhyd. types. The general properties of im portance in plastering are described and details of th e characteristics of, and precautions to be taken w ith, each typ e aro given. Present proprietary makes aro tab u lated according to tvpe.
T. W. P.
H e a t- tr e a tm e n t fo r a s p h a lt c e m e n ts . L. V.
Ga r r ity (Mich. S tate Highway D ept., Highway Res.
Census, 41.321; R oad Abs., 1938, 5, No. 533).—An examination is described of three m ethods of heating to study changes in ductility and penetration of asphalt cements due to th e effects of h eat and air. Treating sand-asphalt mixes in an oven a t 163° gave different characteristics to th e bitum en from those of practice.
The 100-penetration asphalt content te s t had in
herent defects giving erratic results. Blowing air through the m aterial a t 200° for a definite tim e correctly duplicated th e changes observed in practice.
T. W. P.
D e te rm in a tio n of flo w in a s p h a lt b i tu m e n - m in e r a l m ix tu r e s . R . N. J . Sa a l (Arch. tech.
Mess., 1936, 5, T. 8, 2 p p .; Chem. Zentr., 1936, ii, 3037).—The determ ination of penetration, stability, and resistance to pressure is recommended. Deviation of theory from practice is mentioned. A. H . C.
A c id -p ro o f lu te s a n d t h e i r p r o p e r tie s . J.
KxizEK (Chem. Obzor, 1938, 13, 113—116).—Acid- proof lutes m ay be of org. or inorg. m aterial, th e hardening of the la tte r being caused chiefly b y the separation of silicic acid froin th e N a2S i0 3 solution.
The lutes are slow- or quick-hardening, the la tte r being produced by addition of acids, or neutral or basic salts which give insol. silicates. Addition of N a2SiFG aids the hardening. A new lute “ Jo d asta C ” is described,
a strong acid being used to etch th e surface of th e granules of the filler, the size of which is carefully
regulated. P . R.
W e a th e rin g of b u ild in g s to n e s . R . J . Sc h a f f e r
(Chem. an d Ind., 1938, 943—947).—Tho effects of atm . pollution, frost, sol. salts, and biological agencies in causing decay of building stones are described.
Preventive measures against a tta c k include : for new buildings, selection of durable stone, suitable m ortars etc., and suitable design; for existing limestone buildings, washing w ith H 20 a t regular intervals minimises decay. Stone preservatives are not usually effective. Laboratory tests for assessing the w eather
ing quality of stone are outlined. T. W . P.
D e c o m p o sitio n a n d d e a e ra tio n of clay . K . O.
Sc h u l z (Tonind.-Ztg., 1936, 60, 577; Chem. Zentr., 1936, ii, 672).—W eathering of the clay m ay be replaced by a steam treatm en t, followed by cooling
in absence of air. H. J . E.
H e a t- a n d s o u n d -in s u la tio n of b u ild in g s . A.
Mi l l e r (Chem. and Ind., 1938, 982—990).—The m aterials aiid m ethods of construction for heat- and sound-insulation are described and compared. In general, m aterials for heat- and sound-insulation have low and high d, respectively. T. W. P.
E x t e r n a l r e n d e r e d fin is h e s . S u rv e y of co n tin e n ta l p ra c tic e . F . L. Brady an d L. F. Denaro
(Dept.. Sci. In d. Res., Building Res. Bull., 193S, No.
16, 33 pp.).—Cracking and crazing of continental rendered finishes are relatively rare and th e finish can be relied on to be weatherproof. A description of th e m aterials used, the m ethods of application, and th e m ethods of finishing the rendering is given.
M ixtures of lime and cement are m ost commonly used as the binding m edium ; cement alone is rare and CaO alone has poor durability. The m aterial is applied by throwing-on for all coats and never by laying-on, whilst a roughness of tex tu re in finishing (e.g., as obtained by scraping) is common and appears to reduce risk of m oisture penetration, to induce more uniform weathering, and to minimise crazing. The choice of tex tu re for various states of atm . pollution and for architectural design is discussed. T. W. P.
P r o p e r tie s of A u s tr a lia n t i m b e r s . III. P in u s ra d ia ta , D . D on . (P. in s ig n is , D o u g .). In s ig n is , M o n te re y , o r R e m a r k a b le p in e . (Counc. Sci. Ind.
Res., A ustralia, 1938, Pam ph. 81, Div. F orest Prods., Tech. P aper 28,31 pp.).—The mechanical and physical properties of tim ber from P. radiata, and its uses, durability, m ethods of grading, and preservative treatm ent, are described. Various kiln-drying and pressure-creosoting schedules and an extensive biblio
graphy on the pulping of pines are given in appendices.
E. A. R.
C o m p o sitio n of a b n o r m a lly d e v e lo p e d w o o d . J . Wi e r t e l a k and I. Ga r b a c z6w n a (Rocz. N auk roln. lesn., 1936, 36, 395— 405; Chem. Zentr., 1936, ii, 3378—3379).—Narrow annual rings of the wood of Fraxinus americana and of Abies 'pectinata are richer (8%) in lignin and hence have a lower transverse strength (cf. B., 1933, 698), b u t poorer in m aterial sol. in E t 20 -C 0M e2 or C6H 6-E tO H , broader rings containing more cellulose. A. H. C.
Cr.. IX .—B U ILD IN G MATERIALS. 1421 X -R a y in v e s tig a tio n s of th e s t r u c tu r e of w o o d .
W . I . Ca l d w e l l and K . La r k- Ho r o v it z (Physical Rev., 1937, [ii], 51, 998—999; cf. B., 1934, 799).—
Only cellulose patterns were observed in wood samples graded according to origin, conditions of growth,
■mechanical properties, and fibril angle. No indication of th e lignin p a tte rn was found. The presence or absence of fibre structure depends on th e fibril an g le;
when this is large th e p a tte rn is more homogeneous.
Compressed and spring woods have less pronounced fibre structure th a n has summer wood. L. S. T.
“ P h y s io lo g ic a l ” d ry in g of b e e c h w o o d . A. A.
Ja t s e n k o-Ch m e l e v s k i (Compt. rend. Acad. Sci.
U.R.S.S., 1938, 20, 185— 188).—Sawing th e bases of trunks to a depth of several in. 2—3 m onths prior to felling had little effect on th e H 20 content of the wood. Marked drying occurs if felled trees are left
w ith the tops intact. A. G. P.
S w e llin g of b ir c h w o o d . N. A . d e B r u y n e (Nature, 1938, 142, 570—571).—H asselblatt’s d ata (B ., 1926, 747) fit the equation s = a(e— 1)J, where
$ is th e swelling measured as an extension per u n it length and a is a const. The equation is in accord w ith Sementschenko’s theory of absorption (A .,
1927, 1136). L. S. T.
D ry r o t i n w o o d . K . S t. G. Ca r t w r i g h t and W . P . K. Fi n d l a y (Dept. Sci. Ind. Res., Forest Products Res. Bull. No. 1, 1938, 39 p p .; cf. B., 1934, 501).—The dry-rot fungi are described and m ethods for the detection and trea tm e n t of dry ro t aro given in d e ta il; preventive instructions for the use of new tim ber in building construction are included.
E. A. R.
W o o d p r e s e r v a t i o n . K . P e s c h e k (Osterr. Chem- Ztg., 1938, 41, 299—305).—A survey of the conditions of timber decay, and of the methods of preservation
by impregnation. E. A. R.
M y co lo g ica l t e s tin g of w o o d p re s e rv a tiv e s . I I . A rs e n ic a l s u b s ta n c e s . W. Ba v e r d a m m
(Angew. B o t ., 1937, 19, 18—42).—Tests of a no. of preservatives are recorded. The general use of As preps, and m ethods of testing are discussed.
A. G. P.
S e d im e n to m e te r.—See I . T a r . A s p h a ltic b itu m e n fo r r o a d s .—See I I . R e fra c to ry jo in tin g c e m e n ts .—See V III. D u s t c o llec tio n [in c e m e n t w o rk s ] .—See X I. A d h e sio n of w o o d p la s tic s .—
See X III.
Pa t e n t s.
M a n u fa c tu re of e x p a n d e d c e m e n t a r tic le s . W . P . Wi t h e r o w (B.P. 492,280, 16.3.37. U.S., 2.4.36).—A large mass of cement embodying a gas- generating agent is poured into a trough and the articles are formed b y pressing down therein a gang mould, having no top or bottom , before th e expansion
is completed. B. M. V.
M a n u fa c tu re of lig h t- w e ig h t m i n e r a l m a te r ia l.
Br i t. Zo n o l it e Pr o d u c t s, Lt d., Assees. of P . S.
De n n i n g ( B .P . 485,512, 17.3.37. U.S., 27.3.36).—
Relatively fragile granules of exfoliated vermiculite are reinforced by coating w ith a liquid carbonaceous m aterial [e.g., coal-tar pitch) and th en destructively
distilled to produce a hard C residue on th e granules.
The application of th e product in th e h eat-treatm en t of m etals is also described and claimed. T. W . P .
M a n u fa c tu re of (A) [h e a t-]in s u la tin g m a t e r ia ls [as s la b s]? (b) p ro d u c ts c o n ta in in g v e r m ic u lite . (c) H e a t-in s u la tin g c e m e n ts . Br i t. Zo n o l it e
Pr o d u c t s, Lt d. From F . E. Sc h u n d l e r Co., In c. (B.P. 485,504— 6, 17.3.37).—(a) Expanded vermicu
lite, vermiculite laminas, an d small am ounts of fibre are mixed w ith cement slurry, and cast in moulds w ith perforated sides. Excess of H 20 is removed by pressure or suction. P ortland or Mg oxysulphate cement is suitable as binder. An example of th e m ix ratio is (by wt.) : vermiculito 100, cement 45, fibre 18 pts. The laminae and fibres are said to lie along the length of the block when finally prepared, and thereby increase th e therm al resistance across the block, (b) E xpanded vermiculite for use as an aggregate w ith a Mg oxysulphate cement is purified by floating in aq. MgS04, allowing th e im purities to sink, and either removing th e float m aterial to mix w ith MgSO,, solution and MgO, or removing th e heavy m aterial and mixing tho rem ainder w ith MgO. (c) An exfoliated, inorg. porous heat-insulating m aterial [e.g., exfoliated vermiculite, 60—70) is m ixed w ith an org. fibrous m aterial (e.g., hair, 0-5—2) and a m ineral substance (e.g., fireclay, 20—30%) to act as a binder after heating. Asbestos fibres (10— 15%) m ay also be added to th e mix. The org. fibre is intended to hold th e composition together before firing and to cause pores to form after firing. Preferred propor
tions are given. T. W . P .
P ro d u c tio n of l ig h t o r co lo u re d r o a d s u rfa c e s , flo o rin g s, a n d th e lik e . J . R . Geigy A.-G. (B.P.
486,009, 20.11.36. Ger., 21.11.35).—A mass is p re
pared from a light-coloured, pulverulent filler, w ith or w ithout inorg. or H 20-insol. org. dyes, and a H 20 - insol. org. binder (a resin, wax, oil, etc.). This is mixed with a black or dark-coloured mass comprising m ineral fillers w ith tars or bitumens. T. W . P.
P r e p a r in g r o a d -s u rfa c in g p r o d u c ts . Soc. d e
Re c h e r c h e se t d e Pe r f e c t. In d u s t r. ( B .P . 493,898, 13.12.37. Addn. to B .P . 430,061; B ., 1935, 853).—
Fine coal filler is incorporated in an aq. emulsion of ta r, bitum en, or th e like, stabilised by addition of carragheen (I), carob bean, gelatin, etc. A suitable composition is bitum en 35, filler 15, and H 20 50%
[as a 1% solution of (I)]. D. M. M.
S ta b ilis in g s o il m i x tu r e s . In t e r n a t. Bi t u m e n
Em u l s io n s, Lt d. ( B .P . 489,767, 3.2.37. U .S ., 10.2.36).—Soil m ixtures containing < ~ 1 5 % and 5%
of particles w ith diam eter <0-074 and <0-001 mm., respectively, are stabilised b y mixing w ith them a t room tem p. < enough H 20 to bring tho consistency of th e m ixture to th e plastic lim it and an aq. emulsion of bituminous m aterial < enough to act as binder by itself b u t enough to coat th e particles w ith a th in adsorbed film of bitum en capable of preventing re- absorption of H 20 b y th e smaller particles. The m ixture is then air-dried w ithout further m echanical
mixing. D. M. M.
P ro d u c tio n of p ly w o o d , c o m p o s itio n b o a r d s , a n d b u ild in g s la b s . A. Wi g g e n h a u s e r (B.P.
491,973, 18.3.37 and 3.3.38).—Almost any form of cheap cellulosic m aterial is mixed w ith a skim-milk or curd binder, w ith or w ithout a pptg. or hardening medium such as rennet, CH20 , CaO, or cem ent; tho m ixture is moulded, pressed, and
heated. B. M. V.
P r o d u c tio n of co lo u re d a s b e s to s -c e m e n t [tile s, sh e e ts , e tc .]. Tu r n e r & Ne w a l l, Lt d. (B.P.
493,386, 23.7.37. A ustr., 23.7.36).
M o u ld in g of c o m p o site [c o n c re te -s to n e ] b lo c k s fo r b u ild in g , p a v in g , a n d lik e p u rp o s e s . A. B.
Ta y l o r (B.P. 491,397, 6.5. and 2.10.37).
H e a t-in s u la tin g s la b s e tc .—See V III. R u b b e r - c e m e n t p la s tic s .—See X II I. A d h e siv e la y e r s .—
See XV.
X . - M E T A L S ; M ET A LL U R G Y , INCLUDING ELECTRO M ETALLURG Y.
T e m p e r a tu r e a n d h e a t- tr a n s f e r r e la tio n s in th e w o rk in g sp a c e of in d u s t r ia l fu rn a c e s . H . H . Sc h w ie d e s s e n (Arch. Eisenhiittenw., 1937—8, 11, 431—442).— Expressions are derived and graphs constructed for determ ining th e h ea t relations in
steel-treating furnaces. A. R . P.
C a lo rim e tric d e te r m in a tio n of h e a t lo s se s [in m e ta llu r g ic a l fu rn a c e s] d u e to s m a ll q u a n titie s of u n b u r n e d flu e g a s . W. Bu h n e (Arch. W arm e
wirts., 1938,19, 275—277).—A sample of the flue gas cooled to room tem p., and if necessary mixed with air, is burned over an electrically heated P t spiral inside a special type of calorimeter (described), and th e rise in tem p, of a measured q u an tity of cooling-H20 and the current consumption are measured. Experim ents carried out with a ir-H 2, air-to w n ’s gas, and synthetic flue gases show th a t an accuracy of ± 3 % is possible.
R . B. C.
P e r ip h e r a l d is tr ib u tio n of g a s e s i n th e b la s t fu rn a c e . H . W. Jo h n s o n (Blast Furn. Steel P lant, 1938, 26, 590—594, 689—693).—F o ur holes were made in the same horizontal plane about 10 ft. below th e norm al stock line and a t 90° to each other.
Thermocouples were inserted through th e holes and the tem p, was recorded 48 in. beyond th e wall and a t 6-in. intervals up to th e wall. Gas samples were taken a t the wall and in th e stock column. Tables and graphs correlate tem p, an d th e CO and C 02 contents of the gas samples. The relation between variations in th e peripheral gas distribution and furnace-operating conditions is discussed. R . B. C.
E fficien cy of th e b la s t-fu r n a c e p ro c e s s . J . B.
Au s t in (Amer. In st. Min. Met. Eng., Publ. 943,1938, 25 p p .; Met. Tech., 1938, 5, No. 5).—Calculations show th a t the m aterial and therm al efficiencies of the blast furnace, considered both as a smelter and as a as producer, are high. W hilst im provem ents in esign, in control of operation to give a uniform product, and in reducing heat loss by radiation and conduction are to be expected, there is little hope of making a substantial reduction in coke consumption below th a t achieved by th e best m odern practice.
R . B. C.
O p e ra tio n of co ke-o ven g a s -fire d o p e n - h e a r th fu rn a c e s w ith in c re a s e d a d d itio n s of b ro w n - c o a l d u s t. C. E L r e u t z e r (Stahl u. Eisen, 1937, 57, 1397— 1403).—To avoid excessive corrosion of the chequerwork in the recuperators when a high pro
portion of brown-coal du st is used to enrich th e gases,' th e upper courses should be built of bricks containing
> 5 0 % of A120 3 and th e cross-section of tho bricks should d i m i n i s h from top to bottom to allow du st and slag to fall freely. High-Al20 3 packings are practic
ally un attacked by th e slags produced from the coal ash, so th a t these can actually be m elted off the bricks when too much has accum ulated to allow free circulation of th e gases. A. R. P.
D e v e lo p m e n t of th e s m e ltin g of lo w -g ra d e ir o n o re s o n th e b a s is of e n e rg y a n d h e a t-e c o n o m y c o n s id e r a tio n s . E. Se n f t e r ( S t a h l u. Eisen, 1937, 57, 1373— 1381).—Low-grade Fe (e.g., Dogger) ore w ith —20% F e can be economically trea ted by roasting it on a m echanical grate and smelting th e product w ith CaO to obtain a fluid slag containing S i0 2 43, A120 3 20, CaO 28, and MgO 5% . The coke consumption in smelting, provided th a t the charge is free from m oisture an d C 02, is about 1050 k g ./to n of pig F e produced. The Fo contains C 2-5, Si 2, Mn 0-2, P 2, an d S 0-5% and .is suitable for use in place of scrap F e in steel production. A. R . P.
B e n e fits f r o m u s e of h ig h - ir o n c o n c e n tra te s i n a b l a s t fu rn a c e . C. E . Agnew (Amer. Inst. Min.
Met. Eng. Tech. Publ. 956, 1938, 5 p p .; Met. Tech., 1938, 5, No. 5).—The smelting technique developed b y an American firm for New Jersey and eastern Pennsylvania m agnetite ores, so th a t they could compete w ith the more easily reduced Lake haematites;
is described. Successful results were obtained by reducing th e SiO, content of the ore before sintering.
R . B. C.
B la s t-fu rn a c e s la g s . R . S. McCa f f e r y (Blast F urn. Steel P lan t, 1938, 26, 598— 600, 702—703, 719).
—The operation of th e blast furnaces a t Corby steel
works on N ottingham shire F e ores is described.
Desulphurisation of th e Fe is effected outside th e furnace in a ladle by means of soda ash, fluorspar, and limestone. The types of slag which give uniform furnace operation are discussed. R . B. C.
C u p o la o p e ra tio n . D. J . Re e s e (Trans. Amer.
Found. Assoc., 1938, 46, 173—194).— Cupola design, especially w ith respect to th e m ost economical size, and cupola operation and control are discussed.
Tables show coke-bed heights for corresponding blast pressures, and wts. of coke an d F e charges for cupolas of various diam eters. R . B. C.
C lose c u p o la c o n tro l. M. J . Gr e g o r y (Foundry, 1938, 66, No. 6, 38—41, 115— 116; No. 7, 24— 27, 74).—Tho technique adopted by an American firm for producing Fe castings to ten different specifications from base F e obtained from charges of cast Fe, steel scrap, and pig F e is described. R . B. C.
[Device to ] c a tc h c u p o la s m o k e . An on. (Foundry, 1938, 66, No. 8, 32, 86).— A wet dedusting p lan t connected to cupolas a t an American foundry
is described. R . B. C.
Cl. X .—M ETALS; M ETALLURGY, INCLUDING ELECTROM ETALLURGY. 1423 C u p o la fa lla c ie s. D . J . Re e s e ( E o u n d r y , 1 9 3 8 ,
6 6 , N o . 5, 7 2 — 7 3 , 1 4 6 ) . — A n e m p i r i c a l f o r m u l a r e l a t i n g m e l t i n g r a t e t o f u e l - b u r n i n g r a t e , a n d F e t o c o k e r a t i o a n d b l a s t p r e s s u r e , i s g i v e n . R e c o m m e n d e d b e d h e i g h t s f o r g i v e n b l a s t p r e s s u r e s a r e t a b u l a t e d .
R. B. C.
E n r ic h m e n t of h a e m a tite o re s b y flo ta tio n . G. G. Be i n g (Jernkont. Ann., 1938, 122, 139—169).
— Owing to the chemical sim ilarity of th e ore and the gangue, flotation of oxide ores is more difficult th a n of sulphides. The low p u rity of tho concentrate necessitates double or treble flotation and the use of cheap reagents. Swedish haematite (I)-quartz and
— Owing to the chemical sim ilarity of th e ore and the gangue, flotation of oxide ores is more difficult th a n of sulphides. The low p u rity of tho concentrate necessitates double or treble flotation and the use of cheap reagents. Swedish haematite (I)-quartz and