IMO, unless your husband is in a very high level or at least very technically specialised job he would need to arrive with spanish sufficient to be able to work in the mining industry, as it is a totally spanish speaking environment even with the foreign companies, given what your hubbies qualifications are. So in order to work in the mining industry here, you have a few choices -
1. stay in SAfrica a little longer but concentrate on working up into a high level position and on getting a passable level of spanish;
2. Come to chile on a medium term basis (6months minimum) and immerse yourselves in the language, including the technical language he would need for his job, then start applying.
3. Move here permanently and roll the dice.
While there may be a small percentage of people working here in the mining industry that use english as their first language, the vast majority of those can work in spanish and do so on a day to day basis, while official work documents sent back to the international base are handled in english, day to day work is in spanish.