This is one of the most popular and older Spanish strike and union struggle song, born in the coalfield of Asturias. The origins of the song seem to be a traditional Asturian and Galician traditional tavern song. The celebration and tavern Galician folk band, A Roda (The Wheel), made a version of that:
O andar miudiño
¡Ai miudiño!
Miudiño, miudiño…
o que eu traio.
Éche un andar miudiño,
miudiño, miudiño…
o que eu traio.
Que eu traio
unha borracheira de viño
que auga non bebo.
Mira, mira Maruxiña, mira,
mirai como eu veño.
The gently walk
Oh, gently!,/ Gently, gently walk…/ what I’m carrying./ This is a gently walk,/ gently, gently…/ what I’m carrying./ Because I’m carrying such a wine drunkenness/ for I don’t drink water./ Look, look Maruxiña, look,/ look how I’m coming.
Spanish translation/ Traducción al castellano:
https://albokari2.wordpress.com/2009/02/07/cancion-de-mineros-arbol-genealogico-de-una-cancion/
So, as many popular songs, it was converted into a different song that talk about a mining dissater that might occurred in the mine “El Pozo María Luisa” (“María Luisa” pit). For that, the song was called “En el Pozo María Luisa”, “El Pozo María Luisa” or “Santa Bárbara Bendita” –Blessed St. Barbara-, for the thrilling advocation to the mining and miner’s saint patron. Soon, the song became in an anthem for the miner’s strikes and struggles in the last XIX century and all along the XX century (even today) on the North mining regions, as León and Asturias. In Asturias and part of Leon, there are two variants of the song: one in Spanish, and the other in Asturian, or Bable, the non-recognized langage of Asturias:
Nel pozu María Luisa/ Santa Bárbara Bendita
(Asturian version)
Larará
nel pozu Maria Luisa
larará
murieron cuatro mineros
mirai, mirai Maruxina, mirai
mirai como vengo yo
larará
Traigo la camisa roxa
larará
de sangre d´ un compañeru
mirai, mirai Maruxina, mirai
mirai como vengo yo
larará
Traigo la cabeza rota
larará
que me la rompió un barrenu
mirai, mirai Maruxina, mirai
mirai como vengo yo
larará
Santa Bárbara bendita
larará
patrona de los mineros
mirai, mirai Maruxina, mirai
mirai como vengo yo
patrona de los mineros
mirai, mirai Maruxina, mirai
mirai como vengo yo
En el Pozo María Luisa/ Santa Bárbara Bendita
Larará
en el Pozo Maria Luisa
larará
murieron cuatro mineros
mira, mira Maruxina, mira
mira cómo vengo yo
Larará
traigo la camisa roja
larará
de sangre de un compañero
mira, mira Maruxina, mira
mira cómo vengo yo
Larará
traigo la cabeza rota
larará
que me la rompió un barreno
mira, mira Maruxina, mira
mira cómo vengo yo
Larará
Santa Barbara bendita
larará
patrona de los mineros
mira, mira Maruxina, mira
mira como vengo yo
patrona de los mineros
mira, mira Maruxina, mira
mira cómo vengo yo
In the “Maria Luisa” pit/ Blessed St. Barbara
Larará/ In the María Luisa pit/ larará/ four miners were dead,/ (Chorus) look, look Maruxina, look,/ look in which condition I come*.// Larará/ I have my shirt in red/ of a fellow’s blood/ (Chorus)// Larará/ I have** my head broken/ larará/ for it was broken by a blast/ (Chorus)// Larará/ Blessed Saint Barbara/ larará/ miners’ Saint Patron/ (Chorus)
* Literally, the chorus mus say “Look how I’m coming”, but the unknown original singer reffers to the physical condition in which he had come from the mining pit to his home, and not in which transportation way. Maybe I’m wrong, but I’ve prefered not to be ambiguous.
** In Sapnish, depending of the context, traer, “to carry”, and tener, “to have”, can be synonymous. I think this not uses to happen in English.
Another well done translation to English:
http://en.wikipedia.org/wiki/Santa_B%C3%A1rbara_bendita
Many songwriters and folk-groups made their own version of the song, stealthy sometimes. Some of them were the popular Asturian folk-group Nuberu:
At the last 70s, the great folk-band, Nuestro Pequeño Mundo, recorded a version in a LP about the Spanish Civil War songs, under the name (due to contractual troubles) of Coro Popular Jabalón:
And, of course, the most popular Asturian songwriter, Víctor Manuel:
The song must became very popular during the October ‘34 miner rissing, known as the Revolution of Asturias, in which the 
revolutionary Asturian workers took the whole region and were bloody repressed by the Spanish Republic’s right-wing government, with the collaboration of an already famous general named Francisco Franco. In 1976, songwriter Francisco, or Paco Curto, in his conceptual album La Guerra Civil Española, making a travel from the war of Morocco to the Civil War, uses the song for exemplify that tragedy. Listen it: http://www.goear.com/listen/10ad813/santa-barbara-francisco-curto
But other made their own versions… Between 1963 and 1964, the great songwriter Chicho Sánchez Ferlosio recorded a set of revolutionary songs, by his own or traditionals, in Sweden and unsigned (by security), which were recopilated in a LP named Spanska motståndssånger (Sw. “Songs of the Spanish resistance”). Among them was his own version of this song, mixing some Asturian words, in homage to the 1962’s Asturian miner strike, the first since Franco’s victory in 1939. that was repressed with very violence. Obviously, by the time it was recorded, the LP was forbidden in Spain, and was publicated later in 1976:
Canción de mineros
En el Pozo María Luisa
larará
salieron cuatro barrenos,
mira, mira Maruxina, mira
mira como vengo yo.
Larará
murieron los barrenistas,
larará
ayudantes y rampleros,
mira, mira Maruxina, mira
mira como vengo yo
Larará
Traigo la cabeza rota
larará
que me la rompió un costero
mira, mira Maruxina, mira
mira como vengo yo
Larará
Los zapatus tos rasus
larará
de recorrer el rellenu,
mira, mira Maruxina, mira
mira como vengo.
Ya perdí hasta la boïna
larará
por buscar mis compañerus,
mira, mira Maruxina, mira
mira como vengo.
Santa Bárbara bendita
larará
patrona de los minerus
mira, mira Maruxina, mira
mira como vengo
El sol sale para todos
larará
yo aquí dentro no lo veo
mira, mira Maruxina, mira
mira como vengo
Con el pico y con el marro
larará
con el marro y el barreno
mira, mira Maruxina, mira
mira como vengo
haremos un agujero
larará
por ver las luces del cielo
mira, mira Maruxina, mira
mira como vengo…
Miner’s songs
In the María Luisa pit/ larará/ get out four blasts/ (Chorus) look, look Maruxina, look,/ look in which condition I’ve come// The drillers died,/ larará,/ helpers and *diggers* (1)/ (Chorus)// Larará/ I have my head broken/ larará/ for it weas broken by a *stick* (2)/ (Chorus)// Larará/ my shoes are all worn/ larará/ by wandering along the slagheap/ (Chorus)// Even I’ve lost my beret/ larará/ by searching my fellows,/ (Chorus)// Blessed Saint Barbara/ larará/ miner’s Saint Patron/ (Chorus)// The sun is rising for all/ larará/ I don’t see it here deep inside/ (Chorus)// With the pick and with the mallet/ larará/ with the mallet and the blast/ (Chorus)/ we will make a hole/ larará/ to see the lights in the sky/ (Chorus)
(1) My ignorance about the mining world keep me off of making a better translation. I could’nt find what ramplero exactly means, but a statue called “Ramplero” that seems to be a man digging on the ground.
(2) I couldn’t neither find what a costero means in mining. For the context of the lyric seems to be a kind of stick, but I’m not so sure at all.
Trad./ Chicho Sánchez Ferlosio
And at last, but not worst, songwriter and folksinger Elisa Serna, one of the most representative protest singers of Castilia, who in 1974, standing in France, recorded her version in the album Quejido (Moan), edited in Spain, being some songs censured, as Este tiempo ha de acabar (This time got to end). Elisa tells us about another mining disaster:
En la mina El Tarancón
En la mina el Tarancón
se mataron once obreros.
Mira como vengo madre,
mira como vengo yo. 
Se mataron cuatro picas
con sus hermanos rampleros.
Mira como vengo madre,
mira como vengo yo.
Vengo bañao de sangre
de esos pobres compañeros.
Mira como vengo madre,
mira como vengo yo.
Moreda y Caborana
de luto se vistió entero.
Mira como vengo madre,
mira como vengo yo.
Mañana son los entierros
de esos pobres compañeros.
Mira como vengo madre,
mira como vengo yo.
In the “El Tarancón” mine
In the “El Tarancón” mine/ eleven workers were dead./ (Chorus) Look in look in which condition I come mother,/ look in which condition I come.// Four picks died/ with their brothers the diggers./ (Chorus)// I’m bathed in the blood/ of those poor fellows./ (Chorus)// Moreda y Caborana/ dressed all in black./ (Chorus)// Tomorrow will be the burial/ of those poor fellows./ (Chorus)
Trad./ Elisa Serna
La Zamarra de Gustavo 