But work had to continue and the process had to be perfected in order to reduce the cost of the kilo of aluminum produced. Héroult thought of nothing else, as shown in his letters to his young wife, Berthe Belliot, whom he married in august 1888. And again, he succeeded. Jules Dreyfus then decided to focus on the French market. He joined with the Paris Bank of Goldschmidt and together they founded on October 17, 1888, the Société Electrométallurgique Française (SEMF), for the purpose of producing aluminum, of course, but also silicon and various alloys. Héroult, again retained only the technical responsibility for the business, and did not acquire any of the capital.
The new plant of the company, located at Froges, in the Isere, had extremely difficult beginnings. The cost of the kilo of aluminum at the Salindres Pechiney plant, was still too high; the staff broke down, personnel was laid off for incompetence or for financial reasons, right and left, panic set in, and enthousiasm soon flagged.
But Héroult, as usual, was not discouraged and continued to work as one possessed. He built more pots, with four anodes, and then six. This was 1892 and costs began to drop. Our inventor, however, was not satisfied with these results which would have pleased those about him. He wanted to improve both the quality of the product and the profitability of the operation. He succeeded, by lining the pot with a layer of carbon and pitch, reducing the electric voltage to 6 then to 5 volts. The Swiss were aghast in Neuhausen, so were the French in Froges. But with growing charisma, Héroult was able to persuade the Société Electrometallurgique Française to build a new, larger capacity plant, at La Praz in the Maurienne valley. He did not at first participate in its installation, because at the very same time a brand new company, the Société Française de l'Alumunium Pur was experimenting with the new Bayer process. Naturally Héroult was asked to study and evaluate it. His findings led the management of the SEMF to absorb the new company in 1895. This was the beginning of a period of collaboration between Héroult and Bayer, both tirelessly searching for a lower cost in the production of aluminum. Together they went to the United States to study at close range the Hall process, as used in the South Wilmington alumina plant. The process did not appear to give better results than their own. A visit to the British Aluminum Company in England was not the answer either.