Post on 12-Dec-2015
description
Ensayos de FG en SLC
Pruebas usando marcadores físicos (Janelid, 1973)
Comparación pruebas con modelos escalados de arena
Influencia de la geometría de salida en el ancho de extracción
Efecto sobre ancho de extracción
Efecto sobre profundidad de extracción
El ancho aumenta un 20% para el caso de 80° de inclinación
Diseño nivel producción en SLC
•Tipo 1: material tronado fino•Tipo 2: material tronado hasta 0,3 m•Tipo 3: material tronado hasta 0, 6 m•Tipo 4: material grueso con bolones de 0,75 m o más ocasionales
Diseño: ejemplo
Suponga una altura entre subniveles de 25 m
mxhN 50225
Suponga burden de 3 m y 80° inclinado
Tronadura estándar clase 3
Dimensiones de calles es 5 x 3,8 m
De gráfico de diseño
bn= 18 m
Bn( inclinado) = 1,15 * 18 m= 20,7
Bn(inclinado) = 1,1 * 18 = 20 m
Trial design-Ridgeway Mine• Marker design
– Steel pipe, 300mm lengths, 40mm Ф– Filled with grout to simulate rock density– Individual marker IDs welded on markers– Redcaps and Spiders used to hold markers
up hole• Marker Installation
– Installed using explosives charging truck– Grouted into the hole to ensure position is
maintained– Approx. 300 markers in a monitored ring
• Marker Recovery– From magnets on ore handling level– Tests with markers placed into ore passes
show 100% recovery of drawn markers
Ring designs• Blast Rings
– 7 hole pattern– Emulsion 1.1 density– Holes double primed– Pre-charging system
used– 25m sublevel spacing– 6m wide drives– 14m XC spacing
• Marker Rings– 2 – 3 marker fans per
burden– Markers spaced at 1m
intervals down hole– Holes offset in
successive marker fans
AssessmentModeled in 3D to assess
– volume recovered for 20% increments of primary draw
– Volume back break– Width of draw– Depth of draw– Estimated time and location of
dilution entry– Secondary recovery– Tertiary recovery
Back-break recovered previous
ring blast
Primary recovery from blasted ring
Secondary recovery from
level below
Typical primary recovery results• Average width of draw 11-
12m• No interaction between
adjacent rings• Depth of draw variable with
height• Draw proceeds up front of
ring and deepens• Flow cyclic and variable in
individual rings – not the same as in physical models
• Average Primary recovery 60% at 120% draw – consistent across many rings tested