Tailings remediation with dredge mining technologyBart Hogeweg
Tailing ponds are a recognizable phenomenon in the mining landscape. Remediation or re-mining of tailings becomes more important nowadays, pushed by either an economic driver or a an environmental driver, or from both. Historic poor recoveries during processing may have resulted in tailings that still contain significant amounts of recoverable metals. Tailings can also contain metal products that were earlier non-profitable to process further and hence seen as a waste product. These metal products in tailings may be of much more value today due to profitable extraction with modern processing techniques and current commodity prices . Another important reason to remediate tailings is to mitigate any threats and to prevent potential damage to the environment.
Different techniques can be used for tailings remediation. The optimal technique depends on the project conditions and the tailings deposit characteristics. Hydro guns (or monitoring guns) are generally a good technique for tailings heaps. Tailings are loosened by jetting, transported via launders and collected in a sump at the toe of the heap. In case of tailings dams, ponds and beaches, the tailings are likely to be present in a watery environment, making dredging a good solution. A dredger excavates and slurrifies the material and pumps it straight to a processing plant in order to reprocess the material.
Since tailings are already processed at an earlier stage, loosening of tailings during remediation is an easy operation In case of “heavy” materials (e.g. iron), the hydro gun application becomes more challenging due to the deposition of material in the launders. In dredge mining, excavation, slurrification and collection (suction) of tailings occurs simultaneously, making dredging a suitable solution, with wide applications in tailings remediation projects. Different case studies in Chile and Brazil are discussed in this article to illustrate this.
Tailings remediation with dredge mining technologyBart Hogeweg
Tailing ponds are a recognizable phenomenon in the mining landscape. Remediation or re-mining of tailings becomes more important nowadays, pushed by either an economic driver or a an environmental driver, or from both. Historic poor recoveries during processing may have resulted in tailings that still contain significant amounts of recoverable metals. Tailings can also contain metal products that were earlier non-profitable to process further and hence seen as a waste product. These metal products in tailings may be of much more value today due to profitable extraction with modern processing techniques and current commodity prices . Another important reason to remediate tailings is to mitigate any threats and to prevent potential damage to the environment.
Different techniques can be used for tailings remediation. The optimal technique depends on the project conditions and the tailings deposit characteristics. Hydro guns (or monitoring guns) are generally a good technique for tailings heaps. Tailings are loosened by jetting, transported via launders and collected in a sump at the toe of the heap. In case of tailings dams, ponds and beaches, the tailings are likely to be present in a watery environment, making dredging a good solution. A dredger excavates and slurrifies the material and pumps it straight to a processing plant in order to reprocess the material.
Since tailings are already processed at an earlier stage, loosening of tailings during remediation is an easy operation In case of “heavy” materials (e.g. iron), the hydro gun application becomes more challenging due to the deposition of material in the launders. In dredge mining, excavation, slurrification and collection (suction) of tailings occurs simultaneously, making dredging a suitable solution, with wide applications in tailings remediation projects. Different case studies in Chile and Brazil are discussed in this article to illustrate this.
1. Prevención en el ámbito
escolar
Ley 19925
Ley sobre expendio y consumo de bebidas
alcohólicas
2. O Existe evidencia científica que muestra que el
período en donde se concentra el mayor riesgo de
iniciar consumo o desarrollar dependencia a
sustancias adictivas es hasta los 21 años. Después
de esta edad, las probabilidades de desarrollar un
consumo problemático casi desaparecen.
O Los establecimientos escolares constituyen un
espacio ideal para detectar precozmente posibles
factores de riesgo entre los adolescentes y jóvenes.
O Los profesores, así como directores, sostenedores
y apoderados, entre otros actores de la comunidad
educativa, son agentes preventivos debido a su
cercanía con los alumnos, a su papel como
modelos y a su función educadora.
3. O Artículo 42.- El que vendiere, obsequiare o
suministrare bebidas alcohólicas, a cualquier título, a
un menor de dieciocho años, en alguno de los
establecimientos señalados en el artículo 3º, será
sancionado con prisión en su grado medio y multa
de tres a diez unidades tributarias mensuales.
O No obstante, se permitirá la venta, el obsequio o el
suministro de bebidas alcohólicas a menores cuando
éstos concurran a almorzar o a comer, acompañados
de sus padres, a los recintos destinados a comedores.
O Si fuere el administrador o dueño del establecimiento
quien ejecutare la conducta descrita en el inciso
primero, la pena será prisión en su grado máximo,
multa de diez a veinte unidades tributarias mensuales
y clausura temporal del establecimiento, por un
período no superior a tres meses. Iguales penas se le
aplicarán si indujere a menores de edad al consumo
de bebidas alcohólicas, sea directamente o por medio
de publicidad.