19^th CENTURY PHOSPHATE & COPROLITE MINING IN FRANCE

Phosphate was first worked in France in 1846, four years after operations began to extract the Suffolk coprolites. Production began in the Ardennes in 1856, and the Pas de Calais deposits were opened up soon afterwards. (Blakey,A.F. ”The Florida Phosphate Industry” Wertheim Committee, Harvard, 1973,p9,146) By the 1860s production of superphosphate of lime had begun at Nantes, by Monsieur Derrien and near Paris by Monsieur Rohart. They used Norwegian phosphates as well as local supplies from quarries in the Ardennes where, in 1863, J.A. Barral reported in the British Agriculutural Press that

”...from this time be worked up on as vast a scale as the fossil phosphate of lime, since we have seen more than 150 men at work in Mr Coxhery‘s factory. France now begins to draw part of the fertilizing matters which its soil presents to it. A new foreign manure will always be well received, as the wants of agriculture are enormous when it arrives at the maximum of production”

(Mark Lane Express, 28th December 1863)

13.3. L’exploitation des nodules phosphatés des Sables verts de la Meuse et des Ardennes au XIXe siècle, qui a conduit à la découverte de nombreux restes de vertébrés albiens. D’après Stansislas Meunier.

http://www.geowiki.fr/index.php?title=Au_milieu_du_Cr%C3%A9tac%C3%A9

By the early 1870s Edward Packard, the head of an Ipswich-based manure company had started investing on the continent in the search for cheaper phosphate supplies. He had an office in Limburg. He had invested in the Ardennes phosphates, reporting yields of 70%, and was marketing them in Britain by 1874. (Mark Lane Express, 27th April 1874) However, Charles Bidwell, a Cambridge-based surveyor with years of experience in the coprolite industry, gave a talk to the Institute of Surveyors in which he considered such yields as not being permanent, and that exploitation of the French deposits had not been such a profitable investment.

”Considerable sums of money had been launched by men who had tried to import coprolites from abroad, - especially from France, where extensive beds exist in the Ardennes, - but they did not bear the expense of importation, for the reason that the French phosphatic nodules were, frequently, too poor in phosphate of lime, containing as a rule, not more than 40 or 45 per cent., and comparatively much carbonate of lime. Recently an extensive deposit of chalk coprolites has been found opposite to Dover, and in the neighbourhood of Dover itself coprolites had also been found - evidently the same bed extending under the Channel to Calais”.

(Bidwell,C. ‘On Coprolites.‘ Inst.Surv. 1874,p.312)

Léon Bourdon, le frère du pilote du monoplan s'avança et expliqua:

—Nous voulions simplement visiter, au village d'Orville que vous voyez devant vous, une usine où l'on traite le phosphate retiré des terres. C'est assez intéressant pour mériter un instant d'arrêt.

—Il fallait nous prévenir de votre intention avant de quitter Amiens, dans ce cas, répliqua le chef de la caravane, non sans un peu d'humeur. Enfin, puisque nous nous trouvons réunis, nous en profiterons pour faire halte. Nos mécaniciens vérifieront les machines pendant que nous irons voir ces fameux phosphates!...

La chose ainsi décidée, les touristes se dirigèrent vers une usine dont la haute cheminée de briques se découpait sur le ciel et qui indiquait à n'en pas douter, un centre d'exploitation industrielle. Pendant le chemin, M. Léon Bourdon, qui paraissait très au courant de la'question, en sa qualité d'élève chimiste à l'École industrielle de Lille, fournit les explications suivantes aux personnes qui l'accompagnaient:

—Les phosphates d'origine minérale comprennent les apatites, les phosphorites, les coprolithes et les nodules et sables phosphatés. Les deux premières variétés se rencontrent dans les terrains primitifs et servent à la fabrication des superphosphates, car leur teneur en acide phosphorique atteint 32 %. Les coprolithes et les nodules existent dans les terrains crétacés et jurassiques, à l'étage des grès verts et sont exploités dans le Pas-de-Calais, les Ardennes, le Cher, l'Algérie et la Tunisie. Leur teneur en acide phosphorique varie entre 16 et 28 %. Quant aux sables et aux craies phosphatés que l'on exploite ici, ainsi qu'à Beauval et Beauquesne, ils sont beaucoup plus pauvres encore et ils doivent subir un traitement permettant de porter le titre à 50 ou 55 % de phosphate de chaux.

—Par quel procédé? interrogea M. Le Clair intéressé.

—Par le mélange avec des sables plus riches, ou mécaniquement en séparant le carbonate de chaux moins dense du phosphate plus dense, au moyen d'une simple lévigation.

—Et quelle est l'utilité de ces phosphates? demanda à son tour Mme Lhier.

—D'une manière générale, reprit le chimiste, les phosphates doivent être employés comme engrais complémentaires du fumier et des engrais chimiques tels que lé sulfate d'ammoniaque et le nitrate de soude. Leur action est très avantageuse dans tous les sols renfermant moins de 1 % d'acide phosphorique. C'est surtout dans les terres de défrichement riches en matières organiques que les phosphates naturels font merveille, à la dose de 300 à 600 kilogrammes à l'hectare. Cependant on obtient des résultats encore meilleurs avec les superphosphates, sauf dans les cas de terres acides, telles que landes et tourbières.

Les touristes approchaient à ce moment de l'usine aperçue de loin. Ils furent reçus par un vieux comptable qui, ébahi à la vue de tout ce monde lui arrivant, ne savait trop quelle contenance tenir. Enfin, il se mit à la disposition des visiteurs pour les conduire aux hangars où s'opérait le traitement des sables et craies phosphatés, et leur donner les indications nécessaires.

—Ainsi, demanda Breuval, toutes les matières premières que vous manipulez ici proviennent des champs avoisinants?

Le comptable sourit.

—Ah! messieurs, dit-il, on voit que vous êtes tous jeunes et que vous ne connaissez pas la folie des phosphates qui a secoué les populations de la vallée de l'Authie vers 1883.

—En effet, murmura le trésorier, je ne suis venu au monde que l'année d'après.

—Eh bien! messieurs, lorsqu'on a découvert, à cette époque, les premiers gisements de phosphate de chaux sur la colline de Beauval, cela a été comme une épidémie dans tous les villages environnants, tant les habitants avaient été émotionnés des prix fabuleux auxquels avaient été vendus aux Compagnies industrielles d'exploitation, des champs qui n'étaient susceptibles de fournir que de maigres récoltes. Des sondages furent donc opérés sur tous les points, et des paysans jusqu'alors misérables se trouvèrent, du jour au lendemain, enrichis, sinon presque millionnaires, parce que l'on avait reconnu, dans quelque pièce de terre de peu de valeur, la présence du précieux minéral. Oui, messieurs, je me rappelle de ce temps, moi qui vous parle, et je me souviens de la fièvre générale qui agitait les cultivateurs de toute cette région et surexcitait leur cupidité. De pauvres diables, qui eurent la chance de posséder du phosphate dans leur jardin, firent fortune, alors que des agriculteurs plus aisés se ruinèrent à la recherche infructueuse de cette même matière, irrégulièrement distribuée et répartie dans le sous-sol picard.

Les touristes remercièrent chaleureusement le comptable, qui remplissait les fonctions d'administrateur de cette exploitation industrielle, et s'empressèrent d'aller retrouver leurs véhicules.

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In 1875 Professor Augustus Voelcker, an analytical chemist who’d been involved in testing coprolite samples as early as the 1840s, gave an update on the latest imported phosphates:

”In France extensive coprolite beds occur in great abundance, in the Ardennes and other districts; and phosphatic nodules and fossils useful for agricultural purposes have been lately discovered in the south of France as well as in the north. It is chiefly from the neighbourhood of Boulogne, that French coprolites are sent over to England. France further supplies English manure manufacturers with phosphorite, large deposits of which were discovered some years past in the Department of the Loire and Garonne. This deposit is known in commerce as French, or Bordeaux phosphate. It resembles in many respects the phosphorite which is found in Nassau, in the valley of the Lahn, and which is commercially known as German, or Lahn phosphate”.

(Voelcker,Dr.A. On the Chemical Composition of Phosphatic Materials used for Agricultural Purposes,‘ Journ.Agric.Soc.1875,p.399)

Those dug up near Boulogne were hardly distinguishable from those of inferior quality in Norfolk and Bedfordshire. They were dark grey or greenish black coloured hard nodules. The smaller ones were larger than most of the Cambridgeshire coprolites. Their phosphate of lime ranged from 40 to 45% depending upon whether they were well washed and thoroughly dried before shipping. A superior type was found in the valley of the Rhone, near Bellegarde, close to the Swiss frontier, where good specimens of terebratula, belemnites, ammonites, and sea urchins were found. These were lighter in colour than the Cambridge coprolites and more readily ground to powder. Having a phosphate of lime content of between 54 and 60% they were more valuable than the Boulogne coprolites.

”Perhaps the most valuable coprolite deposits in France occur in the Ardennes; these deposits are as yet but partially developed. The cost of carriage is too great to render it probable that French coprolites, except those found close to the coast near Boulogne, will be largely exported into England. It is very doubtful whether the export of the latter will prove a paying speculation, for, as already stated, Boulogne coprolites as a rule seldom contain much more than 45% of phosphate of lime.

They fetch in the market a much lower price than good Cambridge or Bedfordshire or Norfolk coprolites; and under present conditions the importation of Boulogne coprolites into England, at the best leaves but a scanty profit to dealers and exporters.” (Ibid. pp.400-403)

”The discovery of mineral phosphates in the valley of the Lahn, in Nassau, [in 1864] has lately been eclipsed by that of extensive and valuable phosphatic deposits in the valley of the Lot, a tributary of the river Garonne, which flows through the upper and middle beds of the Jura and the lias formations. During the last few years [early 1870s] large quantities of phosphate have been imported into England from the South of France. This phosphate is known in England under the name of French, or Bordeaux phosphate, it being usually shipped from that port. Like Lahn phosphate the French deposit occurs in pockets, and varies greatly in appearance, texture, and in its chemical composition and commercial value. (Ibid p.416)

The more common kinds were yellow or brown, but, despite being dense and hard to grind, were easily dissolved by snow-white colour but sometimes opal-like or grey and the early imports had a phosphate content between 71% and 74%, compared to the 55 - 88% of the German deposits. According to Voelcker, ”...at first only the richer deposits were worked in France and sent over to England, probably with a view of securing a good reception to the newly discovered deposits.”

By 1875, however, the quality had decreased, ”and cargoes, containing on an average not more than 58 to 65% are now not unfrequently shipped at Bordeaux for the English market. It thus appears that either the best quality of French phosphate is already becoming somewhat scarce, or that the increasing demand for phosphatic materials necessitates the exploration of the more abundant deposits of an inferior quality.” As their analysis showed these lower quality phosphates contained, ”more of oxide of iron and alumina than samples of English coprolites equally rich in phopshoric acid, (they) are not worth as much money as the latter.”

This article, of great interest to the buyers for the eighty English manure manufacturers, must have had the effect of reducing their purchases, especially when it went on to detail overseas supplies of significantly higher quality. Evidence shows that their price dropped slightly but there were still imports into London in 1881. See table on page .. )

It is clearly from the neighbourhood of Boulogne, in the North of France, that the French coprolites are sent over to England, and these are largely used for mixing with richer descriptions of phosphates. They occur as dark grey nodules, larger than those of Cambridgeshire, and rich in organic remains. An excessive quantity silicious matter is their chief impurity, and the cause of the low percentage of phosphate of lime, which seldom exceeds 45 per cent.

There are also coprolite beds in FRANCE, in the valley of the Rhone near Switzerland, and in the Ardennes near to Belgium, where it is thought worthwhile to go nearly 200 feet deep through an argillaceous clay to obtain them; but the cost of carriage is too great to allow them to be exported from these places to England.

(Reid, W.C. Mineral Phosphates and Superphosphate of Lime,‘ Chemical News Aug.4th 1876 p.49; Emergence of Rich Phosphatic Chalk in Picardy, especially at Hardivilles and Hallencourt. Quart.Journ.Geol.Soc. vol.xlvii, p356 )

The phosphate mines in the south of France in the Departement of Tarne et Garonne, were discovered by M. Pomerede about 1870. These discoveries were afterwards extended to the Aveyront & Lot departement, the latter turning out to be the most important of all. Two years later they were purchased by the present firm (Packards of Ipswich) who constructed at the same time powerful washing and cleaning machinery. The most important mine, and in fact the largest as yet discovered in the South of France, is the one called Roumagous, situated on the summit of a hill about 1,000 feet above the sea, above the village of Larnagul.

From this mine alone the firm have extracted between 12,000 and 14,000 tons of high class phosphate, analysing over 70%, the residue viz. lower quantities, being left on the spot for further consumption. Fresh experiments are being tried in this mine at a greater depth and it is presumed that there are still a few thousand tons to come out. The next of importance is situated at the top of another hill at a similar height, about a mile to the north. This is now in full working, every facility for extracting the phosphate having been adopted. Several other small deposits are also worked in the immediate neighbourhood. The phosphate is carried down by the peasants to the washing place, where is established a machine of the most improved kind, the phosphate passing in at one end of the cylinder comes out at the other end perfectly clean. The different sizes and qualities are also separated. Nearly 1,00 (sic) men and women are found constant employment in the mines.”

(Norwich Argus c.1870s p.88)

The mineral known as LOT OR BORDEAUX Phosphate comes from the Departments of Lot and Lot et Garonne, in France. It occurs in pockets or fissures and veins of the limestone, and also in thin layers, near the surface. These are covered with an alluvial soil and clay, containing phosphates, but much contaminated with iron and other impurities. The pockets, of all shapes and sizes, and sometimes reaching 100 feet deep, are generally traced and indicated by narrow vertical veins of deposit, which rise from them to the surface, and are mostly found on the highest ground. It varies greatly in appearance, texture and composition. Occasionally it is found in snow-white compact masses, breaking with an earthy fracture, and a modest degree of hardness. The more ordinary kinds are dark yellow or brown, dense and hard; but it is frequently found of a dark agate colour, somewhat resembling the inside of broken flints, of a waxy lustre, stratified and intersected with thin layers of oxide of iron. It has the appearance of being an aqueous deposit; and the probable cementing together of lumps of phosphate, bones, &c., with more or less alluvial clay and earth, by the percolation of dissolved phosphatic matter, may account for the appearance, texture, and composition of some f the portions. The white specimens are the richest, some being as high as 85 per cent, with a minimum 1/2 per cent of iron &c., but the bulk of cargoes received here only contain 70 to 72 per cent, and with 4 or 5 per cent of iron &c. Fossil bones and teeth are found in quantity. The surface phosphatic deposits find a ready sale on the spot...The best varieties of these phosphates are well adapted for the manufacturer of superphosphate. Most of the large Lot mines are owned and worked by English firms, amongst which is a Newcastle Company (Langdales).

(Reid,W.C. ‘Mineral Phosphates and Superphosphate of Lime,‘ Chemical News Aug.4th 1876 p49 p49-50)

Lawes Chemical Manure Co. London Imports of Boulogne coprolites 1873 – 1881

1873 1000 Boulogne 35/-

1873 100 Boulogne 35/-

07/1881 1000 Boulogne 30/-

9/08/1881 500 Boulogne 9d per unit

1/11/1881 150 Boulogne 32/6

(Valence House Museum, Dagenham, Lawes Chem.Man.Co.Minute Books)

Apatite, mineral phosphate of lime, was also found at St. Gothard, in Switzerland. and translucent, wine yellow asparagus stone or spargelstein variety found in Zillerthal and Greiner, in the Tyrol. Way, p253